Ailunce HS1 User Manual

Ailunce HS1 User’s Manual

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Ailunce HS1 USER’S MANUAL

Ailunce HS1 User’s Manual

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Preface:

This manual is for the HS1 transceiver, a good color tft display
screen for it and good trx. As an open-source SDR (Software
Defined Radio), both in terms of Software and Hardware. As such,
the features of this transceiver will continue to evolve and this
manual is intended to provide a reference source.

Main Features

• Spectrum Dynamic Waterfall Display

• Multiple Working Modes：Receive Mode, Transmit Mode,

TUNE Mode, VFO Mode, SPLIT Mode

• DSP Digital Signal Processing Noise Reduction

• Automatic Notch Filter

• Receive Fine Tuning Function, Changeable MIC Gain Value

• VCC Power Supply Voltage Indication Table

• Transmit Signal Strength Display Table

• Multifunctional Instrument：SWR Standing Wave Ratio Meter,

AVD Audio Frequency Meter, ALC Signal Modulation Meter

Parameter：

Frequency Range

RX：0.5MHz-30MHz
TX：0.5MHz-30MHz

Output Power

Maximum 15W

Receiving Sensitivity

Better than -115dBm

Operating Mode

Full Modes

Operating Voltage Range

DC 9-15V

Dimensions

190mm*69mm*45mm

Maximum Current

3.5A

Transceiver comes with automatic key generator circuit, Can
be connected to the use of automatic keys.

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Figure 1:Front panel controls of the HS1 transceiver

Power ~ This turns the transceiver on, but it is also used to turn
the transceiver off and save configuration and frequency
mode/memories. A brief press of this button will also select the
brightness of the LCD backlight. Please read notes about the

backlight and the possibility of its injection of a tone into the
receiver when a “dim”mode is selected. Low brightness will

cause the noise inside the machine to increase, and there is no
such noise at 100% brightness.

Important:
If you have not already done so, please find the menu
item “RX/TX Freq Xlate” and set it to “RX Low LOW”
as this will improve receive and transmit performance.

See this item's menu description in this manual for more
details.

Band-, Band+ ~ These buttons select the next lower or higher
amateur band. When the lowest or highest band is reached it
“wraps around” to the highest/lowest band. Pressing and holding
the Band- along with the Power button may be used to turn
on/off the automatic backlight blanking feature while pressing
and holding the Band- and Band+ buttons will toggle between
the display of the Spectrum Scope and Waterfall Display

STEP-, STEP+ – This sets the tuning step size in steps that
include 1 Hz, 10 Hz, 100 Hz, 1 kHz, 10 kHz, and 100 kHz. The
function of these buttons may be swapped via a menu setting.
Pressing and holding of one of these buttons will temporarily
change the step size to facilitate tuning in smaller or larger steps
while pressing-and-holding both of these buttons simultaneously
will toggle “frequency lock” on and off, with “on” being
indicated by the main Frequency readout being displayed in
grey.

FREQ ENC – This is used to tune the transceiver's operating
frequency, the tuning steps being set by the STEP- and STEP+
buttons.

ENC1,AF – Rotary encoder ENC1is typically used to adjust the
volume, but its function may be changed using button AF to
adjust the side tone gain

ENC2, RF – Rotary encoder ENC2 is typically used to adjust
the RF gain (or squelch in FM mode but its function may be
changed using button RF to adjust the action of the DSP Noise
Reduction or Noise Blanker strength. In the Menu mode it is

Front Panel controls:

simplicity they are typically defined as follows:

All of the controls are defined in software, but for the purpose of

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used to select the item to be adjusted. Pressing-and-holding
button RF when in normal (non-menu) receive mode will
switch between the right-hand function adjusting the DSP Noise
Reduction or the Noise Blanker “strength.”

ENC3, RIT – Rotary encoder ENC3 is typically used as an
RIT (Receiver Incremental Tuning) but its function may be

changed using button RIT to adjust the sending speed (in Words
Per Minute) in the CW mode, or to adjust the Microphone or
Line-In gain in voice mode. In the Menu mode it is used to
modify the item selected, or button RIT may be
pressed-and-held to select whether Microphone-In or Line-Input
mode is active and to be adjusted.

Mode – This button is used to select the operating mode of the
transceiver (CW, USB, LSB, etc.) Pressing this button cycles
through the available modes.Pressing-and-holding this button
will allow the selection of a mode that is disabled in the menu
system (e.g. AM.)
When “LSB/USB Auto Select” is enabled, pressing button
Mode will skip the sideband that is not appropriate for the
frequency of operation (e.g. USB will not be selected below 10
MHz) but pressing-and-holding this button when LSB is
displayed will change the mode to USB – and
Pressing-and-holding again will change it back to LSB. When
menu item “LSB/USB Auto Select” is enabled, in order to
change to AM you must select a mode other than LSB (or USB)
– such as CW – and then press-and-hold button Mode - AM will
then be selected.

DSP – This button is used to control the DSP audio filter mode.
Pressing-and-holding will turn DSP on/off while preserving the
current settings. Pushing this button will also “reset” the DSP.

PA – This button is used to set the transmit power level (FULL,
5 Watts, 2 Watts, 1 Watt, 0.5 watts, and back to FULL.)

Note: The power is automatically limited to 2 watts in
AM Transmit mode. When in CW, LSB or USB mode
(those modes with a “BFO”) pressing-and-holding this
button will cause a tone with a frequency equal to that
of the CW sidetone and transmit shift to be sounded.

Figure 2: Main display of the HS1 transceiver

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BW – This button is used to select the audio pass band filter of
the receiver. Pressing-and-holding this button will force the
selection of bandwidth that are otherwise disabled. The
filter-selection function of this button is disabled when the FM
mode is selected, but pressing-and-holding it while transmitting
on FM will cause a tone burst to be generated, if this feature is
enabled.

Buttons F1-F5 are “soft” buttons located under the display, the
functions of which change depending on mode, indicated on the
LCD itself and will be discussed in more detail later in this
document.

Also on the front panel are two LEDs, LD1 on the left and LD2
on the right. LD1, which is typically green, is illuminated on
receive and LD2 which is typically red is illuminated on transmit.

Main Display：

Figure 3: The main screen (annotated) with the SPLIT function activated.

When “Frequency Translate” mode is on, the center frequency indicator

will be shifted to the left or right of center by 6 kHz.

On the main display, just above the Spectrum Scope, there are a
number of indicators:

• Main Frequency Display: This may be displayed
either as a single frequency (transmit/receive as in
Figure 2) or as a “Split” display as shown in Figure 3
with separate transmit and receive frequencies. If the
numbers in this display are grey the “Frequency
Lock”(toggled by pressing-and-holding both the STEP-
and STEP+ buttons simultaneously, or configured in
the menu)is active. If this display is yellow, a
transverter offset has been configured.

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• RIT+Tuning Display: Above and to the right of the
main frequency display is a smaller display that is offset
from the main display if the RIT is set to something other
than zero.

• Band Display: To the right of the main display is an
indicator of the amateur band in which the current
frequency is tuned. If the current frequency is outside an
amateur band it will display “Gen” (e.g. “General
Coverage”).

• Mode Indicator: Above the “10's” digit of the main
frequency display is the current mode displayed on a blue
background.

• Step Size Indicator: Above the center of the main
frequency display, between the Mode Indicator and the
“Sub” Frequency display is the setting of the current step
size. In Figures 2 and 3 the step size is set to 1 kHz.
Optionally, a “marker” may be activated that puts a line
under the digit indicating the currently-selected step size
(see the menu item “Step Size Marker”).

Along the top there are a number of additional indicators:

• TCXO Mode/Display: In the top-left corner the
“TCXO” box indicates whether the TCXO
(Temperature-Compensated Xtal Oscillator) is active or
not. The TCXO is used to read the temperature of the
Si570 synthesizer (U8 on the RF board) - which should be

thermally-bonded to the temperature sensor, U10, with a
piece of copper or aluminium - and apply a
compensation to it to keep on frequency. When it is active
the bar graph below the temperature display will display
white dots with a blue marker that moves about but when
set to “Off”, the bar graph will be grayed out. If set to
“Stop” the temperature display will be replaced with
“STOPPED”. In Figures 2 and 3 the TCXO is set to ON
and displaying a temperature of 112.5F, but this may be set
to display the temperature in Centigrade. If the temperature
is very low(below 0C or 32F)this will display dashes and
the temperature compensation will be disabled until the
temperature-coupled synthesizer/sensor exceed this
minimum threshold.

• S-Meter: This S-meter is nominally calibrated so that S-9
equals 50 micro volts into a 50 ohm load with each S-unit
representing 6 dB. Practically speaking, the usable range of
the S-meter ranges from about S-3 to something a bit
higher than “40 over” which, if you were “run the
numbers” about matches the dynamic range of the
receiver! The bottom half of the S-Meter's graticule
(“S0-S9”) is normally white in color, but if the receiver's
A/D converter experiences an overload condition, it will
turn red. On bands with strong signals it is normal for this
to momentarily flash red as the internal gain control adjusts
itself. In Figures 2 and 3 the S-meter is displaying a signal
level of S-9.

• PO: The S-Meter scale, when in transmit mode, also

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indicates the output power from the transmitter.

• Multi-function display: Below the S-Meter and Power
Output meter is a multi-function meter that, using button
F2, may be used to select one of three modes:
SWR,AUDIO, and ALC.

• SWR: When in transmit mode, this meter indicates the

calculated VSWR.Note that the VSWR is calculated only

when the forward power exceeds 0.25 watts. When in

SSB mode, this indicator will not show any VSWR

indication unless/until there has been some RF power that

exceeds the minimum power, allowing a calculation to be

made.

• AUD io: This indicates, in dB, the relative audio level

being applied to the MIC/Line input.

• ALC: This indicates, in dB, the amount of gain reduction

that the ALC is applying while in transmit mode. 3-12dB of

indication during typical speech is normal.

Along the left-hand edge there are a few more indicators,
starting from the bottom-left corner:

• VCC: Below this is a voltmeter that indicates the current
supply voltage.Below 9.50 volts, the digits are displayed in
red, orange below 10.5 volts and yellow below 11.0 volts.
The receiver may function as low as 8 volts, but obtaining
more than 3-5 watts of “clean” transmitter power may not
be possible below 10.5 volts, particularly on the higher
bands.

• FIL: Below this is the current filter bandwidth setting,
selectable by using button BW. In Figures 2 and 3the
bandwidth is shown being set to 2.3 kHz.

• Power Output Setting: Just above the FIL icon is the
currently-selected output power setting, selectable using
buttonG3. In Figures 2 and 3the power is shown being set
to 5 watts.

• DSP Setting: Just above the Power Output Setting is the
indicator of the DSP mode. The modes available are:
“OFF”,“NR”(Noise Reduction), “NOTCH”, and
“NR+NOT”(Noise Reduction and Notch).

Spectrum display:

Below the frequency readout, shown in Figure 2andFigure 3is a
spectrum display that shows signals that are on either side of the
current tuned frequency. Along the bottom of the spectrum display
is a frequency scale that shows the frequency scaling of the
graticules rounded to the nearest kHz. This display works very
much like a spectrum analyzer with the vertical scale being
represented logarithmically, the number of dB/division being
selectable by the user. To further the analogy to a spectrum
analyzer, the“reference level”(the signal level at which a particular
strength is indicated) is automatically adjusted via an AGC
(Automatic Gain Control) within the spectrum scope that operates
independently from the receiver's AGC that automatically scales
the strongest signal within the passband such that it is at/near the
top of the scope–this, to allow the representation of widely varying
signals on different bands without the need of user adjustment.

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Waterfall display:

Figure 4 shows an alternate method of displaying signals near the
currently-tuned receiver signal is the Waterfall Display. In this
mode, the frequency is displayed along the “X” (horizontal)
axis,just as in the case of the Spectrum Scope but instead of the
signal strength being displayed as height, it is displayed as relative
“brightness”. The waterfall displayed is so-called because it can
convey the history of recent signal in time by showing the most
recent signals at the bottom,but when new signals are analyzed,
the older signals are displaced vertically and the newest signals
are placed along the bottom. In this way, one has a quick visual
“history” of what has occurred not only on the center frequency.

Figure 4: A typical waterfall display in the "Magnify" mode

showing +/- 12 kHz (24 kHz) of a band segment. When "magnify"

mode is NOT active +/-24 kHz (48 kHz) of a band is visible.

Options available to both the Spectrum Scope and Waterfall
Display:

• An adjustable “smoothing” filter (menu item “Scope/Wfall

Filter”) is available that dramatically improves the visibility of
rapidly-changing signals In the menu system, the range of the
Spectrum Scope may be set to span either +/- 24 kHz or +/- 12
kHz, with the scope's AGC operating only on signals within the
displayed span – see the menu setting “Spec. 2x magnify” for
more information.

• Also available are “Window function” selections that operate on
the input FFT data to both the Spectrum Scope and the Waterfall
Display that pre-process the spectral data to minimize “spill-over”
of adjacent FFT “bins”. What this can do is make the Spectrum
Scope and Waterfall display look “sharper” and prevent a strong
signal from “leaking” over and covering a weak one.

Connectors:

On the right-hand side of the transceiver on the UI board are four

3.5mm three-conductor connectors. Starting from the top, these
connectors are:

• Line Out (J1). This is a receive audio output that is fixed
level (unaffected by the volume control) that may be used to
supply audio to a computer for “sound card” (digital) modes.
This connector also carries the audio being transmitted.

• Line In (J2). This input may come from a computer for
“sound card” (digital) for transmitting. Its use must be
selected in the menu for it to be used.

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• Microphone/PTT (J3). This connector has both a
microphone connector with bias voltage (if R68 is installed)
for powering an electret microphone and a PTT
(Push-to-Talk) line that is shorted to ground to key the radio.
While the PTT line is always active, the microphone must
be selected as the active audio input from the menu for it to
be used. (Note that this is also the “Dah” line, which is also
used for keying in CW “straight key” mode.)

• Speaker/Phones (J4). This jack feeds and external
speaker/headphones, disconnecting the internal speaker when
something is plugged into it.

• Warning: There is no limiting resistor in series with
this audio connection, so you must remember to turn
down the volume before plugging in headphones.

On the RF board, along the right side, there are three connectors.
Starting from the top these connectors are:

• Power connector (J1). This is a coaxial power connector,

5.5mm O.D., 2.1mm I.D., that supplies power to the
transceiver. The outer shell is negative and the inner
conductor is positive.

• Paddle (J2). This connects to either a set of Morse paddles
or a straight key. The outer conductor (“ring”) is typically the
“Dah” while the tip is the “Dit” when in Iambic mode. In
“Straight Key” mode only the outer conductor (“ring”) is
used. (The “Dah” line is the same as the “PTT” line.)

• Accessory (J3). This is used for interfacing with an
external device and may be used for keying the transmitter
and/or determining when the transmitter is keyed. The “tip”
of this jack is the “PTT”/”Dah” line and may be used when
interfacing the transceiver to a computer when operating a
digital mode. The outer conductor (“ring”) is grounded
when the transceiver is in transmit mode and this may be
used to key an external amplifier or TR switch.

• The upper, “A” type (full-sized) USB connector is a USB
host port that may have future use for storage of data/audio
files and/or interface devices such as keyboards and wireless
devices. It is also possible to load firmware from a USB
memory stick from the interface.

• The lower “mini” USB host port is primarily used for
programming firmware into the transceiver.

On the left-hand side of the UI board are two USB connectors.

Finally, the sole connector on the left-hand side of the RF board is
the BNC-type antenna connector, the nominal impedance being 50
ohms.

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Operational modes and functions:

After powering up, the HS1 transceiver will revert to receive
mode on the last frequency, in the mode and using the audio
bandpass filter that was in use when it was last powered down
using the POWER button. In this mode LD1, the left-hand LED
(typically green) is illuminated.

By default, ENC1 controls the volume, ENC2 the RF Gain and
ENC3 controls the RIT.

When in transmit mode LD2 (typically red) the right-hand LED is
illuminated. In transmit mode most of the controls are frozen, this
being done to prevent the change of frequency, filter type and
mode during mid-transmission.

Tune mode may be entered by pressing the button located below
the TUNE icon on the screen (e.g.button F5) at any time and in
this mode a carrier is generated, along with an audible sidetone in
the speaker, the amplitude being set by the “Sidetone Gain” (STG)
setting. The output power may adjusted during transmit by
pressing the button PA to cycle through the settings. The TUNE
label on the LCD will turn red while TUNE mode is active.

Pressing the TUNE button again will exit.

Receive mode:

Transmit mode:

TUNE mode:

Always have a suitable load connected to the transmitter
(matched antenna or dummy load) before entering TUNE mode
or ANY transmit mode.

Notes:

When not in Menu mode, “soft” button F4, beneath the display. This button

toggles which VFO, A or B, is currently the “Active” VFO. This display

will change, always indicating the currently-active VFO.

If SPLIT mode is not active, the currently active VFO's frequency, filter

selection and mode are used for both receive and transmit.

If SPLIT mode is active the currently active VFO's frequency and filter are

used for receive while the “other” VFO's frequency is that used for

• When in TUNE mode audio being input to the Microphone and

LINE inputs will be ignored.

• When TUNE is activated in SSB mode, the frequency offset from

the display frequency and the sidetone frequency (e.g. the tone

emitted from the speaker) will always be 750 Hz.

• Note: There will be no tone in SSB-TUNE mode when frequency

translation is active.

• When TUNE is activated in CW mode the frequency offset from the

display frequency and the sidetone frequency will be that configured

as the sidetone frequency in the menu.

• Pressing-and-holding the TUNE button will toggle the Transmit

Disable function. If this is activated the TUNE indicator above button

F5 will be displayed in grey and pressing it will have no effect. The

“Transmit Disable” function may also be enabled/disabled in the

configuration menu.

VFO A (or VFO B):

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transmit: The transmit mode is always that of the “active” (receive) VFO.

The SPLIT mode will be discussed in more detail below.

If one PRESSES AND HOLDS this button (F4) the currently active VFO's

mode, filter setting and frequency are copied to the inactive VFO with an

on-screen indication that this has taken place.

When not in Menu mode, “soft” button F3 toggles “SPLIT” mode
on and off.

When SPLIT mode is off the radio behaves normally, using the
currently selected VFO for both receive and transmit.

When SPLIT mode is on, the radio uses the currently-selected
VFO's mode for both receive and transmit, the current VFO's filter
and frequency for receive and the “other” VFO's frequency for
transmit. In this mode, the main frequency display is also changed,
showing both the receive and transmit frequency, separately.

To set up for SPLIT mode one might do the following:

• Activate the SPLIT function. “SPLIT” has now changed color and the

display shows two frequencies.

• Suppose that a DX station is transmitting on 14.155 and

receiving on 14.165, USB. In that case, you would transmit on 14.165

and receive on 14.155.

• Dial in your transmit frequency of 14.165 MHz – the receive

frequency of the DX station.

• Press the VFO A/B button to move that frequency to the “other”

VFO: That is now your transmit frequency.

• Dial in your receive frequency of 14.155 – the transmit frequency

of the DX station – and also set USB mode and your desired filter

bandwidth.

• You are now ready to go! - It doesn't matter which frequency is in

VFO A or B.

• When installing and then using this firmware for the first time

there may be a problem with saving the VFO A/B frequencies. After

using the POWER button to save the settings once or twice it

appears as though the memory locations get properly initialized and

that they work as they should thereafter.

• The SPLIT mode works only on the same band – this to prevent the

destructive battering of the band-switch relays that might occur with

crossband operation – which would also slow down transmit/receive

switching.

• When using FM mode it is possible to use the SPLIT function for

repeater operation if one VFO contains the repeater input frequency

and the other contains the repeater output frequency. By “swapping”

the VFOs one may also do a “reverse” function and listen to signals

on the repeater's input frequency.

Important Comments related to SPLIT mode and VFO A/B:

◎Note that it is possible for one to set the STEP to 100 kHz

and using the main knob to tune the receive frequency to

another band and operate split that way, but this is not

recommended and you do this at your own risk!

SPLIT:

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In “normal” operation the spectrum display will be visible on the
screen and the five “Function” buttons along the bottom of the
display will have the following functions:

“Soft” buttons in normal operation:

• MENU (button F1) – This enters the menu system, allowing the

configuration of the transceiver. Pressing and holding this button will

save all settings to EEPROM.

• METER (button F2) – This button selects the mode of bar graph

below the S-meter which is used to display different parameters while

transmitting. Repeatedly pressing this button selects, in turn, the display

of SWR, AUD and ALC.

• SPLIT (button F3) – This button toggles “SPLIT” mode on/off. When

on (“SPLIT” is yellow), the transmit and receive frequencies are

separated using VFO A and B as shown on the main frequency display.

• VFO A or VFO B (button F4) – This button toggles whether VFO A

or VFO B is the “primary” VFO. The VFO that is being displayed is

ALWAYS the one being used for receive.

• TUNE (button F5) – This button toggles the TUNE mode on/off.

Pressing and holding this button will disable transmit as indicated by

this indicator being displayed in gray.

Pressing the MENU button (e.g. button F1) will enter the main menu system

by which many parameters of the transceiver may be configured: These

parameters will be discussed in detail later. Pressing-and-holding this button

will save all settings to EEPROM.

Upon entering the MENU mode several of the “soft” buttons along the

bottom of the screen willchange their function:

“Soft” buttons in MENU mode:

• EXIT (button F1) – This exits the menu system, returning to the

main display. Pressing-andholding this button will save all settings to

EEPROM.

• DEFLT (button F2) – This button resets the currently-selected item

to its default setting.

• PREV (button F3) – This button goes backwards one screen or six

menu items. Pressing-andholding this button will jump to the

beginning of the menu, or to the end of the menu if already at the

beginning.

• NEXT (button F4) – This button goes forwards one screen or six

menu items. Pressing-andholding this button will jump to the end of

the menu, or to the beginning of the menu if already at the end.

• The TUNE mode remains present while in the MENU system at

button F5

Note: If an item has been changed in the menu system that may
need to be saved to EEPROM using the POWER button, the
MENU indicator will be orange and be followed by an asterisk
(e.g. “MENU*”)

Configurable options on the main screen:

In the upper left corner there are a number of items on the main
screen that are configurable using the buttons and/or encoders

• AFG - “AF Gain” (a.k.a. “Volume Control”). This is used to adjust

the audio level feeding the speaker/headphone jack using encoder

ENC1. Button M1 may be used to select whether this encoder adjusts

AFG or STG (see below) with the “un-selected” item being “grayed”

out. AFG (e.g. the “Volume control) is always enabled when in Menu

mode.

• STG - “Sidetone Gain” while in CW mode. This is used to adjust the

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level of the sidetone that is heard during keying while in CW mode

and while in TUNE mode using encoder ENC1. Button M1 may be

used to select whether this encoder adjusts STG or AFG with the

“unselected” item being “grayed” out. Sidetone Gain is also

adjustable from the main menu. When not in CW mode this is

replaced with “CMP”.

• CMP - “TX Compression Level” while not in CW mode. This is

used to adjust the amount of audio compression when in voice mode.

When in CW mode this is replaced with “STG”.

• RFG - “RF Gain”. This control, as the setting is decreased, causes

an increased deflection in the S-Meter and a commensurate decrease

in the receiver sensitivity. This functions in exactly the same way as

the “RF Gain” control on a traditional analog receiver and is typically

used to limit the receiver sensitivity on a noisy band. Button M2 may

be used to select whether this encoder adjusts RFG or NB (see below)

with the “un-selected” item being “grayed” out. This

parameter may also be adjusted from the main menu.

• DSP – This adjust the “strength” of the DSP noise reduction, when

enabled. Pressing-andholding button M2 will select between this

parameter or “NB” (Noise Blanker adjust) being visible. Turning the

DSP on and off will also reset the DSP noise reduction/notch engine.

• NB - “Noise Blanker”. This control adjusts the “strength” of the

noise blanker, with “0” being “disabled.” This is a “pulse” type noise

blanker operating on the wideband input prior to filtering in the DSP

input. As the noise blanker strength is increased, the color of the

number changes to warn the user that the higher numbers are more

likely to cause degradation of the receive audio. Button M2 may be

used to select whether this encoder adjusts NB or RFG with the

“un-selected” item being “grayed” out. Pressing-and-holding button

M2 will select between this parameter or “DSP” being visible.

• RIT - “Receive Incremental Tuning”. This offsets the receiver, in 20

Hz steps, to allow the transmit frequency to be different from that of

the receiver with the actual receive frequency being shown on the

“sub” frequency display above and to the right of the main frequency

display. Button M3 may be used to select whether this encoder adjusts

RIT or WPM (see below) with the “un-selected” item being “grayed”

out.

• WPM - “Words Per Minute” while in CW mode. This adjusts the

Morse sending rate in “Words Per Minute” when using Iambic mode

keying. Button M3 may be used to select whether this encoder adjusts

WPM or RIT (see below) with the “un-selected” item being

“grayed” out. The Morse WPM setting may is also adjustable from

the main menu. When not in CW mode this is replaced with “MIC”

or “LIN”.

• MIC or LIN - “Microphone Gain” or “Line Input Gain” when not

in CW mode. This adjusts the Microphone (or Line Input) gain,

depending on which is enabled. When in CW mode this is replaced

with “WPM”. Pressing-and-holding button M3 will select

Microphone or Line-Input modes. Note that if this is changed during

transmitting, one must briefly unkey for the change of inputs to take

effect.

Automatic switching of on-screen items when going from
receive to transmit:

Using the item in the “Configuration Menu” labeled “O/S Menu
SW on TX” and setting it to ON several of the on-screen items

will change automatically when going from receive to transmit and
back again when returning to receive when in SSB mode: This

function is NOT available in CW mode.

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14

These parameters include:

▪ This automatic switching facilitates the adjustment of the relevant

parameters when in transmit mode without having to pause and press the

M1 and/or M3 buttons to switch the functions of the relevant knobs.

▪ Note that if you already had selected an alternate function while in receive

(e.g. “CMP”) it will “remember” and return to that setting after you have

been in transmit and again turned to receive.

▪ Setting the parameter “ O/S Menu SW on TX” to OFF prevents the above

parameters from changing when going between receive and transmit.

Button G2 is used to enable/disable the DSP function, providing the

following settings:

Pressing-and-holding button G2 will “save” the currently-selected DSP

mode, if on, and turn it off. Pressing-and-holding this button again will

restore the mode(s) that had been configured when it had been turned off.

The “strength” of this filter may be adjusted using the menu item #10, “DSP

NR Strength” - but be very careful with this as it easy to go overboard with

this setting. If it is set too high, the artifacts caused by the noise reduction

(e.g. “hollow” or “watery” sound) can be worse than the interference

thank you are trying to remove!

• CMP (in voice mode)

• MIC or LIN (in voice mode)

DSP (Digital Signal Processing) Noise Reduction and
Automatic Notch Filter:

• OFF – DSP Functions are turned off

• NR – Noise Reduction only

• NOTCH – Automatic Notch Filter only

• NR+NOT – Noise Reduction and Notch Filter

The “strength” may also be set using button M2 and ENC2 without having

to enter the menu system. To do this:

IMPORTANT OPERATIONAL NOTES related to DSP and
the noise blanker:

• Enable DSP “NR” mode by pressing button G2.

• Press button M2 so that the highlighting changes from RFG to

DSP on the screen.

• If “NB” is displayed instead, press-and-hold button M2 to

change it.

• With DSP highlighted, ENC2 will now allow adjustment of the

DSP noise reduction “strength”.

• You will note that the number denoting DSP “strength” is greyed

out when DSP is turned off and cannot be (accidentally!) adjusted.

• All DSP functions are disabled until a few seconds after the radio

boots up.

• The notch filter is automatically turned off in CW mode. It cannot

be selected when in CW mode. The reason for this is that the notch

filter would “kill” CW signals!

• ALWAYS turn all DSP modes off when you are using any “sound

card” (digital) modes such as PSK31, RTTY, SSTV, etc. DSP is

NOT compatible with these modes!

• The noise blanker is always disabled in the wide bandwidth (5, 6,

7.5 or 10 kHz) mode.

• The noise blanker is disabled in AM mode.

• Enabling the noise blanker and DSP can cause the user interface of

the HS1 to slow down significantly! What this means is that the

response to button-presses and the updates of the

spectrum scope can be significantly slower. (You have been warned!)

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There are additional “advanced” configuration settings related to the DSP

modes available: See the items in the menu system and the section on

“Advanced DSP Setting.

Warning:

• The DSP Noise Reduction and the Automatic Notch Filter

(“Notch”) are separate functions that operate independently. Because

of this, operating on “NR+NOT” mode takes more processor

“horsepower” than either “NR” or “NOTCH” alone.

• The noise blanker takes about as much processor power as both the

DSP NR and “Notch” put together which is why turning on the noise

blanker in addition to DSP can significantly slow down the

transceiver's response – and also why the noise blanker is disabled in

AM mode and when set to a wide bandwidth mode – either of which

take more processor power in their own right!

• When DSP NR is active, the parameter “DSP NR FFT NumTaps”

can significantly change processor loading: The higher this value, the

more loading. If you need to have DSP turned on, but you find the

user interface to be operating too slowly, try setting this to a lower

value: This can decrease the “quality” of the noise reduction

somewhat, but it will free some processor power.

Tips to minimize processor loading when using DSP:

It is possible to select the combination of wide bandwidth, DSP noise

reduction and DSP Notch (e.g. “NR+NOT”) while in AM mode. This

combination can “stall” the radio with too much processor power,

making operation sluggish and result in distorted audio. If you do

this, you may press-and-hold the DSP button to disable DSP and

“un-select” some of these options.

Using the HS1 Transceiver – Brief Overview

Figure 5: Front panel controls of the HS1 transceiver

Note:

If you are unfamiliar with the HS1, please refer to the section
of the manual: “Before you get on the air - Initial set-up of

the HS1 transceiver”

To turn on the transceiver, press the POWER button briefly and
the display should light up, go through its attribution and boot-up
screen and display the frequency and spectrum display.

Receive:

• Adjust volume using the ENC1 control.

• Tune the frequency using FREQ ENC knob. Select the step
size using the STEP- and STEP+ buttons.

• Pressing-and-holding the STEP- or STEP+ button will

temporarily decrease/increase the step size while tuning, the step

size display changing colour while this is in effect.

• Pressing-and-holding both the STEP- and STEP+ buttons at the

same time will enable/disable the “Frequency Lock” mode. The

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16

main frequency display will turn grey when “Frequency Lock” is

enabled. The RIT is still enabled when the frequency is locked.

• Change the band using the BND- and BND+ buttons.

• Change the mode (USB, LSB, CW, etc.) using button G1. Note:

Pressing-and-holding this button will force the selection of

“disabled” modes.

• Button G4 selects the receiver bandwidth.

Note: Pressing-and-holding this button will force the selection of

“disabled” bandwidths.

• Pressing button G2 will select the mode of DSP noise reduction.

• If RIT is desired, use ENC3 to shift the receive frequency: The

small frequency display will show actual receive frequency

display when RIT is set to non-zero, but the large display will

show the transmit frequency.

• Pressing and holding button G2 will turn DSP off,

saving the current settings while pressing and holding

again will restore the last-used mode. The available DSP

modes are:

There are certain configurations where some/all of the DSP

functions are not available. For example, the notch filter is

disabled in CW mode (for obvious reasons!) and DSP is

completely disabled in FM mode.

• NR = Noise reduction only

• NOTCH = Automatic notch (tone) filter only

• NR+NOT = Both Noise reduction and Automatic

notch filter.

Transmit:

Initial SSB transmit audio set-up:

Set the receive frequency and mode, setting the desired output
power using button G3. Note that it is recommended that for

voice modes that “full” power not be used unless you have
carefully configured for clean, linear output power.

• Preferably, connect the HS1 transceiver to a 50 ohm dummy load

capable of handling at least 10 watts. Alternatively, you may tune to a

clear frequency while connected to an antenna with a known-good 50

ohm match.

• Use button G1 to select LSB or USB mode as desired.

• Press button F2 to select the AUD io meter.

• For testing, press button G3 to select the 0.5 watt setting: The power

setting does not matter for this configuration.

• Connect the microphone to connector J3: This is is the one just

above the speaker connector on the right side of the UI board, below

and to the right of the FREQ ENC control. The HS1 is typically used

with an electret-type microphone element and power for the

microphone element is supplied by the radio.

• Press button M3 to switch from RIT to MIC. If the box to the

right-hand side of RIT shows “LIN” which indicates that line-input

mode is active, press-and-hold button M3 to change it to MIC. Press

button M3 as necessary to highlight MIC on the display: This allows

the adjustment of the microphone gain.

• Now, key the radio using the Push-to-Talk (PTT) button on the

microphone: The spectrum display should freeze.

• Speak normally into the microphone. You should see the indicator

on the AUDio meter bounce upwards. While speaking, adjust the

ENC3, which adjust the MIC parameter, so that the AUDio meter

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17

indication peaks up to +4 or so (in the red) on peaks. Occasional,

higher, higher peaks are permissible, but avoid settings that cause

full-scale indications which could imply distortion.

• Release the PTT button and press button F2 to select the ALC

meter.

• Press button M1 to highlight the CMP on the display: This will

allow the adjustment of the compression level of the speech

processor.

• Press the PTT button and speak normally again. You should see

the ALC meter indicate upwards on voice peaks occasionally: If it

does not, increase the MICrophone gain slightly.

• Adjusting CMP to a higher value will increase the

aggressiveness of the speech processor: A value of 2 is a nice,

modest value and a value of 12, while very “punchy” and can be

used to maximize “talk power” will sound very “processed” and is

likely to be unpleasant for normal, casual QSOs. The value of

“SV” will select custom settings – see the menu for additional

information.

• Once you have configured the settings to your satisfaction,

press-and-hold button F1 to store them in memory.

What to do if you notice that the ALC or AUDio meters jump
when you key your microphone:

• In a quiet room with an antenna or dummy load connected to the HS1, set

the METER mode to ALC and key the microphone/transmitter without

talking and note if ALC meter jumps at the instant that you key the

transmitter and goes down again. Next, switch the METER mode to AUD

and key the microphone/transmitter again, watching the AUDio meter.

▪ If you notice that either meter jumps upwards when you key the

transmitter and drops down again your keying the transmitter may be

electronic “click” or mechanical “clunk”, “de-sensing” the transmitter's

ALC. This can be caused by the the powering-up of the electret element in

the microphone when the radio is keyed and/or by the (noisy!) mechanical

action of the switch – but the result can be the same in either case: A

temporary “desense” when you start talking and/or an annoying sound heard

by the station receiving you!

• To minimize this adjust menu item “TX Mute Delay” which will keep the

microphone audio muted for a short period after keying up. The parameters

are adjustable from 0 (off) to 25, which keeps the audio muted for a full 250

milliseconds (one-quarter of a second) after the microphone is keyed.

▪ It is recommended that one finds the minimum value to reliably suppress

the appearance of the microphone key-up noise and then increase it by 50%.

◎ AM transmission operates the same way as SSB, but frequency

translation mode must be activated. Remember also that the

unmodulated carrier in AM will be ¼ that of the PEP power in SSB!

Important information regarding the “Frequency Translate”
mode:

• Menu item “RX/TX Freq Xlate” selects the enabling/disabling of

baseband frequency translation in the receiver/transmitter. When the

translation is active, instead of the receiver operating at and around "DC",

the signals are mathematically shifted from 6 kHz (above or below –

user-selectable). Whether or not frequency translate mode is enabled is

displayed on the start-up splash screen.

• Performing this frequency shift can help forgive a lot of the "sins" that

occur with "DC" conversions - the most obvious of which are that ANY

noises in the power supply as well as the 1/F noises of op amps, mixers,

Comments when using AM:

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18

A/D converters and the like tend to show right up in the received audio.

With the signals at microvolt levels, it is a real fight to minimize these

signals! These signals/problems can show up as:

It should be noted that these code modifications DO NOT relieve the

builder of the strong recommendation that one perform the modifications

in the "HS1 Board Modifications" file, particularly the U3a and MCU and

LCD power supply modifications (for UI board 0.3) but they should go a

long way toward reducing the artifacts that can still occur even after making

those modifications - even to the point of gaining an extra S-unit or two in

sensitivity.

Menu item “RX/TX Freq Xlate” has the following options:

• Hum

• Howling

• Audio feedback, particularly at higher volumes

• Buzzing with the dimming of the backlight

• Noises from the I2C communications (e.g. “ticking”)

• OFF - This is the original operation of the transceiver with the

receive (and transmit) signals operating at and around zero Hz.

• RX LO HIGH - In this mode the signals are shifted BELOW zero

Hz by 6 kHz, requiring that the local oscillator be shifted up by the

same amount. The received signals are tuned at the first graticule left

of center on the spectrum scope.

• RX LO LOW - In this mode the signals are shifted ABOVE zero

Hz by 6 kHz, requiring that the local oscillator be shifted down by the

same amount. The received signals are tuned at the first graticule right

of center on the spectrum scope.

For various reasons (e.g. the use of USB on higher bands where the

potential for zero-HZ interference is highest) the use of “RX LO LOW”

is recommended for best performance!

Quirks and side-effects:

When the translate mode is activated and “magnify” mode is not turned on

you will note that the receive signal is no longer in the center of the

spectrum scope! Along the bottom of the spectrum scope you'll observe

that the frequency display is changed, with the frequency in kHz being

displayed in full under the graticule, being shifted left or right as noted

above.

If you have used other SDR software – particularly “sound card” SDR

rigs on computers – you will already be familiar with this sort of shift!

Using the HS1 with computer “Sound Card” (e.g. digital) modes via the

Line-Input and Line-Output connections:

The HS1 may be connected to a computer, tablet or smart phone via audio

cables and the PTT line on the Microphone cable to allow modes such as

SSTV, PSK31, WSPR or other digital “Sound Card” mode. To do this,

configure the transceiver as follows:

• Using button G1, select USB mode: All digital modes are operated

using USB, regardless of band. In this way the audio frequency of the

digital signal may be added to the frequency display to calculate the

actual transmit/receive frequency.

• Set RIT to zero using ENC3: Press button M3 as necessary to

highlight RIT to allow adjustment. When using a digital mode the RIT

MUST be disabled or else you will have difficulty making contacts!

• Set CMP to zero using ENC1: Press button M1 as necessary to

highlight CMP to allow adjustment. When using a digital mode, the

audio compressor must be set to MINIMUM (0) or else it may

degrade the digital signal!

• Before connecting the external device (Computer, tablet, phone) set

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the audio output level to mid-scale. Also set the audio input gain to

approximately mid-scale as well.

• For receive, one may use any of the available receive audio filters,

but it is recommended that the Wide filter not be used! If narrow

(300Hz, 500Hz or 1.8 kHz) filters are used, one may shift the center

frequency of that filter in the menu to suit the passband for that

mode, but be aware that it is possible to run too narrow a filter for

some of the “wider” digital modes! In the vast majority of cases the

2.3kHz filter will be adequate.

• Be certain that DSP filtering is turned off! The DSP noise

reduction or notching on any radio necessarily alters signals and

doing so can degrade them, making them difficult for the attached

computer/device to decode!

Connect the Line-Input jack (J2) of the HS1 to the audio output of the device

you are using to generate the audio and connect the Line-Output jack (J1) of

the HS1 to the audio input of that same device.

To key the transceiver, you will need also to connect a cable the Microphone

jack (J3 on the UI board) or the Key jack (J2 on the RF board) and the

PTT/Key line on either of those jacks (the “ring”) would be grounded to key

the transceiver: Typical rig-computer interfaces will easily accommodate this

connection.

• Preferably, connect the HS1 transceiver to a 50 ohm dummy load

capable of handling at least 10 watts. Alternatively, you may tune to

a clear frequency while connected to an antenna with a known-good

50 ohm match.

• Using button M3, select LIN mode. You may need to

press-and-hold this button to change from MIC to LIN. Press

button M3 as necessary to highlight LIN.

• Using button F2 select the AUDio meter.

• Using button G3 set the HS1 to 0.5 watts for this setup.

• Using the program running on the external device, key the computer

using the selected mode. If the program has a “test” mode, use it for

this.

• Adjust the LIN setting via ENC3 for a reading on the AUDio meter

of +2 to +4.

• Make sure that you have set “CMP” to 0 as noted above!

• Un-key the transceiver.

• Make a note of the settings that you have used for future reference.

• Find a signal on the bands representative of the mode and adjust the

audio input level of the external device for approximately

“mid-scale”. The Line Output level on the HS1 on this version of

firmware is fixed.

• It should be noted the the LINE OUT jack will contain the transmit

audio. This is an artifact of the hardware configuration.

• Once you have configured the settings to your satisfaction,

press-and-hold button F1 to store them in memory

TUNE mode:

The operation of the TUNE mode is very simple:

The TUNE button may be used to send an unmodulated (CW) carrier for

brief testing, such as checking the RF power output or the VSWR/matching.

The TUNE function is also used for initial adjustment of various parameters

(TX Gain, Phase) as described elsewhere in detail.

• Press the TUNE button: The HS1 transmits and the indicator turns

red.

• Press the TUNE button again: The HS1 stops transmitting and the

indicator turns white.

Comments about the TUNE mode:

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20

• When set to CW mode, when TUNE is activated the HS1 will

produce a carrier above the dial frequency by the amount of the setting

of the “CW Side/Off Freq” (e.g. sidetone frequency).

• When set to SSB mode, when TUNE is activated the HS1 will

produce a carrier that is offset from the dial frequency by 750 Hz – the

same as the audible sidetone. This carrier will be below the dial

frequency in LSB mode and above it in USB mode.

• Pressing-and-holding the TUNE button will toggle the TRANSMIT

DISABLE function. If this mode is on, the TUNE indicator will turn

gray and all transmit capabilities of the HS1 will be disabled. This is the

same as the parameter “Transmit Disable” in the configuration

menu.

• TUNE mode does not function in AM mode.

• Note: There will be no audible sidetone in “SSB TUNE” mode

when Frequency Translation is enabled.

Configuration of the HS1 for CW operation:

• Connect a key or paddle to jack J2 on the RF board: This is the

connector next to the DC power input.

For connecting a paddle for Iambic keying:

• The TIP of the connector is DIT.

• The RING of the connector is DAH.

Note: The “dit” and “dah” may be swapped using the “CW Paddle

Reverse” menu setting.

For connecting a straight key, mechanical semi-automatic key (e.g. a

“bug”) or an external

• The RING of the connector keys the transmitter.

Note that the DAH/Straight Key connection is the same as the “PTT”

line on the Microphone connector.

Now, press the MENU button (F1) and use the NEXT and PREV buttons

(F4 and F3, respectively) to navigate to the screen containing the menu item

“CW Keyer Mode”, noting the setting to the right of it. The three possible

settings are:

• IAM_A – Iambic mode “A”. Using paddles, alternate dots and dashes

are sent with both paddles are depressed, stopping with the last dot or

dash that was sent while the appropriate paddle was depressed.

• IAM_B – Iambic mode “B”. The same as mode “A” except that

keying continues by sending one more element – a dot if the paddles

were released during a dash and vice-versa.

• STR_K – Straight Key. This would be used for a straight key, a

“bug”or external keyer/computer.

• CW Paddle Reverse – This reverses the DIT and DAH positions of

the paddle, affecting ONLY the IAMBIC modes when using the built-in

keyer.

• CW TX->RX Delay – This sets the delay, after the last CW element,

before the transceiver returns to receive mode.

• CW Side/Off Freq – This sets the offset frequency and sidetone in

CW operation, adjustable in 10 Hz steps.

Additional items on this menu (you may need to scroll to another screen

using ENC2) include:

◎ Note: If the sidetone frequency is adjusted, the center

frequencies of the 300 Hz and 500 Hz filters should be adjusted

to compensate to keep the frequencies within the center of the

filter passband!

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• The parameters CW Keyer Speed and CW Sidetone Gain are

adjustable from the main display and will be discussed shortly.

• CW Freq. Offset – This sets the display/shift mode to be used for

CW operation: For more details on this parameter, see the MENU

section.

• Press button G1 to select the CW mode.

• Press button G4 to select the desired receive audio bandwidth.

• Press button G3 to set the power to 0.5 watts: The power has little

effect on this adjustment.

• Press button M3 to highlight the WPM parameter: Use ENC3 to set

the desired sending speed in words-per-minute. This parameter has

no effect if set to straight-key mode.

• Press button M1 to highlight the STG parameter: ENC1 is used to

adjust this parameter.

• Press the paddle/key to cause the HS1 to transmit: Use ENC1 to

adjust the volume of the sidetone. Note that the volume control

(“AFG”) setting has no effect on the level of the sidetone.

• Once you have configured the settings to your satisfaction,

press-and-hold button F1 to store them in memory.

• The DSP “NR” (Noise Reduction) mode may be used to advantage

when in CW mode, but note that the DSP “NOTCH” mode is always

disabled because it would “kill” CW signals!

• The sidetone frequency is exactly that of the amount of transmit

offset from the dial frequency.

• If the parameter “CW Side/Off Freq” is changed - which changes

the sidetone/offset frequency - remember to change the the center

To configure for CW operation:

Miscellaneous notes and tips:

frequencies of the 300 Hz and 500 Hz filters so that the center of your

receive filter passband will match your transmit frequency. If you do not

do this a station that returns to you on your frequency may do so outside

the passband of your receive filter!

• There is a slight interaction between the power setting, the perceived

loudness of the sidetone gain and the sidetone gain setting. This is a

known issue, but it has not been a cause of complaints.

• NOTE: Refer to the menu item “CW TX/RX Offset“ to set up the

transceiver for USB, LSB or “Automatic” USB/LSB operation as

desired. You may also configure the transceiver so that the frequency

displayed is that of the transmit carrier frequency or that of the received

signal when its pitched is matched to that of the transceiver's sidetone.

• Pressing-and-holding button G3 when in CW, LSB or USB mode will

generate a tone that is equal in frequency to the CW sidetone and

transmit-receive offset. This may be used to “spot” the frequency so that

you can transmit on the same frequency as the station with which you

are communicating. The loudness of this tone may be adjusted using the

“Adjustment Menu” option “Beep Volume”.

It is recommended that one NOT operate CW when the menu is

being displayed!

If the menu is being displayed, CW element timing will be

disrupted!

The configuration menu system:

The configuration menu may be entered by pressing the MENU button (F1).

When in the menu system, it may be navigated using the following encoders

and buttons:

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• ENC2 – Selects the individual menu item.

• ENC3 – Adjusts the selected menu item

• Button F1 – Exits the menu system, returning to the main

transceiver display. Pressing-and-holding will save settings to

EEPROM.

• Button F2 – Resets the currently-selected item to its default

setting.

• Button F3 – Goes backwards in the menu system by 6 items (one

screen). Pressing-and-holding this button will jump to the beginning

of the menu, or to the end of the menu if already at the beginning.

• Button F4 – Goes forwards in the menu system by 6 items (one

screen). Pressing-and-holding this button will jump to the end of the

menu, or to the beginning of the menu if already at the end.

• Button F5 – Enters/Exits TUNE mode. Pressing-and-holding this

button will also toggle “Transmit Disable”. The “TUNE” indicator

will turn gray indicating that the transmitter is disabled.

• When in MENU mode ENC1 is always configured as AFG (e.g.

the volume control.)

• Whenever a menu item is changed the warning “Save settings

using POWER OFF!” will appear along the bottom of the screen to

warn you that any changes that you may have made will NOT be

saved unless you power down the transceiver using the POWER

button.

• If you have made any changes while in the MENU system, when

you exit the MENU system the label above button F1 will be

orange and display “MENU *” to warn you that you should power

down using the POWER button to save any changes that you might

have made.

Important Notes:

There are two separate menus within the menu configuration system:

• The MAIN menu. These are the more commonly-adjusted items with

the labels in YELLOW.

• The CONFIGURATION menu. These are less-frequently adjusted

items used for calibrating

The CONFIGURATION menu is hidden unless it is enabled by activating it

by setting the last item in the main menu to ON.

Note:

All menu items are numbered, but the numbers are omitted here to

simplify maintenance of this document as these numbers occasionally

change as features are added/modif

Main Menu configuration items:

Important Note:

If, when the a menu item is changed, it will be necessary to
turn off the transceiver using the POWER button to save the
changes to the EEPROM.

Alternatively, button F1 may be pressed-and-held to cause a
save of all settings to occur.

It is strongly recommended that one NOT attempt to
operate CW when the menu is being displayed! If the
menu is being displayed, the CW element timing will be
disrupted!

These items are listed in the order that they appear in the menu system.

DSP-related items:

• DSP NR Strength – This adjusts the aggressiveness of the DSP

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23

noise reduction, with 0 being “weak” and higher numbers

correlating to “stronger” DSP noise reduction effects. The relative

effects of this parameter are affected by the “advanced” parameters –

see the “DSP Related Items” section. This is the same as the “DSP”

parameter controlled by ENC2 on the main screen.

• 300Hz Center Freq. - This sets the center frequency of the 300 Hz

CW filter, the options being 500, 550, 600, 650, 700, 750, 800, 850

and 900 Hz. A final option is “Off” which eliminates this filter from

the selection when button G4 is pressed. The settings will be

displayed in white if this filter is currently selected.

• 500Hz Center Freq. - This sets the center frequency of the 500 Hz

CW filter, the options being 550, 650, 750, 850 and 950 Hz. A final

option is “Off” which eliminates this filter from the selection when

button G4 is pressed. The settings will be displayed in white if this

filter is currently selected.

• 1.8k Center Freq. - This sets the center frequency of the 1.8 kHz

“narrow” SSB filter, the options being 1125, 1275, 1427, 1575 and

1725 Hz. A final option is “Off” which eliminates this filter from

selection when button G4 is pressed. The settings will be displayed in

white if this filter is currently selected.

• 2.3k Center Freq. - This sets the center frequency of the 2.3 kHz

SSB filter, the options being 1262, 1412, 1562 and 1712 Hz. The

settings will be displayed in white if this filter is currently selected.

This filter cannot be disabled.

• 3.6k Filter. - This enables/disables the filter and when set to “Off”,

this filter will be eliminated from selection when button G4 is

pressed. The settings will be displayed in white if this filter is

currently selected.

Filter-related items:

• Wide Filter Select - This selects the “wide” filter – that is, the next

bandwidth above the 3.6kHz bandwidth with four bandwidth being

available: 10 kHz, 7.5 kHz, 6 kHz and 5 kHz. If one of the “AM” items

is selected (e.g. “5kHz AM”) then the selected bandwidth will be

available only in AM mode but if a “non-AM” item is selected (e.g.

“5kHz”) then this selection will be made available in SSB mode as

well.

• Wide Filt in CW mode – When ON, the “Wide” SSB filters (3.6

kHz and Wide) will be available for selection when in CW mode.

• CW Filt in SSB mode – When ON, the “Narrow” CW filters (300

Hz and 500 Hz) will be available for selection when in SSB mode.

• AM mode disable - When ON, the AM mode will be eliminated

from selection when the G1 button is pressed. Note that it will still be

available if one presses-and-holds button G1.

• LSB/USB Auto Select – This enables the automatic selection of LSB

or USB, depending on the current band. The available settings are:

When “LSB/USB Auto Select” is enabled, pressing button G1 will

skip the sideband that is not appropriate for the frequency of operation

(e.g. USB will not be selected below 10 MHz) but

pressing-and-holding this button when LSB is displayed will change

the mode to USB – and pressing-and-holding again will change it back

to LSB.

When “LSB/USB Auto Select” is enabled, in order to change to AM

• OFF – No automatic selection.

• ON – LSB is selected < 10 MHz, USB is selected >= 10 MHz

• USB 60M – LSB is selected < 10 MHz except for 60 meters

and USB is selected >= 10MHz. This setting has been provided

for those areas where USB is typically used on 60 meters (e.g.

the U.S.)

Ailunce HS1 User’s Manual

24

you must select a mode other than LSB (or USB) – such as CW – and

then press-and-hold button G1: AM will then be selected.

• FM Mode Enable - When set to ON the FM mode is available with

normal presses of the G1 button. Note: Even when off, it may still be

accessed if button G1 is pressed-and-held in CW mode. If the AM

mode is also set as being disabled, you may have to press-and-hold

G1 again to get to FM.

• FM Sub Tone Gen – This selects the frequency of the subaudible

tone (in Hz) to be transmitted on FM: The setting of “off” (default)

disables the tone. The deviation of this tone is approximately +/-300

Hz in “Narrow” mode and +/-600 Hz in “Wide” mode.

• FM Sub Tone Det – This selects the frequency of the subaudible

tone (in Hz) to be decoded on FM: The setting of “off” (default)

disables the tone decoder so that only “carrier squelch” is used. When

this is active it is necessary that both the squelch be opened AND the

tone decoded in order for audio to be heard. The “FM” mode indicator

on the main display will be backgrounded in red when the selected

tone is being decoded.

• FM Tone Burst – This enables and selects the transmission of a

“tone burst” (a.k.a. “whistleup”) that might be used to activate some

repeaters. Two frequencies are available: 1750 Hz and 2135 Hz. The

tone burst is activated by pressing-and-holding button G4 while

transmitting.

• FM RX Bandwidth – This selects the detection bandwidth when in

FM mode: Selection of “audio bandwidth” via button G4 is disabled

as it is irrelevant in FM mode and this setting is unlikely to be

changed very often. The selections are:

FM mode-related items:

◎ 7.2 kHz – This is suitable only for “Narrow” operation and

even this will result in a bit of added distortion as the filter about as

narrow as it may be to pass audio. Using this setting the weak-signal

sensitivity is the highest amongst the FM filter bandwidth settings

since this narrowest filter also intercepts less noise under weak-signal

conditions.

◎ 10 kHz – This is the “default” bandwidth and is suitable for

“Narrow” bandwidth and while it will work for “Wide” bandwidth,

slight distortion may occur on voice peaks.

◎ 12 kHz – This is wider than necessary for “narrow” bandwidth and

recommended for “Wide” bandwidth.

◎ Operation of “Wide” (+/-5kHz) on “Narrow” frequencies will result

in “loud” audio, possible “squelch clamping” and splattering onto

adjacent “narrow-spaced” channels.

◎ Operation of “Narrow” (+/-2.5kHz) on “Wide” frequencies will

result in chronically “low” audio, reduced “copyability” under

weak-signal (noisy) conditions and everyone telling you to talk

louder!

• FM Deviation – Two “modes” of FM are available: “Narrow” with +/-

2.5 kHz peak deviation (w/1kHz modulation) and “”Wide” with +/- 5 kHz

peak deviation, the former being commonly used on HF and the latter

being that which is used on VHF bands except for those instances where

the “narrow” (+/- 2.5 kHz) mode is specifically used. These two modes

are more or less interoperable, with the following provisions:

Ailunce HS1 User’s Manual

25

AGC and other receiver-related items:

• AGC Mode - The selections are SLOW, MEDium, FAST,

CUSTOM and MANUAL. These related to the “decay” speed (e.g.

“hang”) of the receive AGC. When in MANUAL mode the AGC is

disabled and the audio gain is set to maximum – see “RF Gain”,

below. WARNING:

Reduce volume level before setting this to MANUAL!

• RF Gain - This is the same as the “RFG” (RF Gain) control from the

main menu and in this context it is used in conjunction with the

MANUAL AGC mode.

• Cust AGC (+=Slower) - When AGC Mode is set to CUSTOM this

sets the decay rate with a higher setting setting a slower decay. A

setting of “12” is equal to the “MED” AGC setting. Values lower than

3 are displayed in RED to warn the user that the decay rate of the AGC

is likely to be extremely fast, that the resulting audio is likely to be

unpleasant and that a bit overshoot/undershoot is possible on the tail

end of a signal. This parameter is displayed in orange if CUSTOM

AGC mode is not selected.

• RX Codec Gain - Normally set to AUTO, this determines whether

or not the A/D input gain on the Codec is automatically controlled

based on the input signal levels. If the input levels start to approach

full-scale, the gain of the coded is automatically reduced, but if these

level have not been attained for a while, the gain is gradually increased

again. If this is set to anything other than AUTO there is the risk of

significantly reducing the dynamic range (e.g. performance) of the

receiver. When not in AUTO mode, the settings range from 8, which

is “maximum” gain and the highest susceptibility to overload to 0

which is the lowest receiver sensitivity. Settings other than AUTO are

indicated in RED to warn the user of likely receiver degradation.

• RX NB Setting - This is the same as the “NB” setting on the main

screen. This adjusts the “strength” of the noise blanker, with “0” being

off.

• RX/TX Freq Xlate – This enables the mathematical translation of the

receive signals, shifting them from “zero” (e.g. around DC) to + or – 6

kHz. This feature can reduce issues related to direct-conversion

receivers such as audio feedback, power supply noise and other noise

sources that can degrade receiver performance. The selectable options

are:

• The noise blanker takes a significant amount of processor

horsepower, so some “slowing” of responses should be expected

when it is active, particularly if DSP is turned on at the same time!

• The noise blanker is disabled when the menu is displayed, when

in AM mode or if a wide bandwidth is selected.

• OFF - This is the original operation of the transceiver with the

receive (and transmit) signals operating at and around zero Hz

(e.g. baseband operation.)

• RX LO HIGH - In this mode the signals are shifted below zero

Hz by 6 kHz, requiring that the local oscillator be shifted up by the

same amount. The received signals are tuned at the first graticule

left of center on the spectrum scope.

• RX LO LOW - In this mode the signals are shifted above zero

Hz by 6 kHz, requiring that the local oscillator be shifted down by

the same amount. The received signals are tuned at the first

graticule right of center on the spectrum scope. For various

reasons (e.g. the use of USB on higher bands where the potential

for zero-HZ interference is highest) the use of “RX LO LOW”

is recommended for best performance!

Ailunce HS1 User’s Manual

26

For more information, refer to the section about Frequency

Translation near the end of this document.

• Mic/Line Select - This selects whether the Microphone or the LINE

input is to be used for transmit audio in the SSB mode. This is the same

function as pressing-and-holding button M3 when in a voice mode.

• Mic Input Gain - This is used to adjust the microphone input gain to

adjust the drive in SSB mode. It is recommended that the AUDio meter

be used, setting this parameter for audio peaks above “0dB”. This setting

cannot be adjusted if the MIC input is not selected.

• Line Input Gain - This is used to adjust the line input gain to adjust

the drive in SSB mode. It is recommended that the AUDio meter be

used, setting this parameter for audio peaks above “0dB”. This setting

cannot be adjusted if the LINE input is not selected.

• ALC Release Time - This adjusts the release (decay) time of the ALC.

A value of 10 is offers modest compression while values of 5 or lower

offer fairly aggressive compression. See the section about the

adjustment of the ALC/Compressor. This setting will be displayed in

RED and not adjustable unless “TX Audio Compress” is set to “SV”.

• TX PRE ALC Gain - This is a post-filter, pre-ALC gain setting in the

TX audio path where a setting of 1 is unity. This is increased from unity

to increase the amount of ALC action (compression). See the section

about the adjustment of the ALC/Compressor. This setting will be

displayed in RED and not adjustable unless “TX Audio Compress” is set

to “SV”.

• TX Audio Compress - This is the same as the “CMP” setting on the

main screen and it adjusts the amount of compression of the transmitted

audio signal. This parameter dynamically adjusts both “ALC Release

Time” and “TX PRE ALC Gain” to provide a configuration that will

Transmit Audio related items:

result in a small amount of compression for low values or “heavy”

compression for high values. When set to “SV” (which would be

setting “13”) the “ALC Release Time” and “TX PRE ALC Gain”

parameters, above, are available for adjustment to provide “custom”

processor settings. The “ALC Release Time” and “TX PRE ALC

Gain” settings forced by this parameter are not saved to EEPROM and

the user-configurable settings in “SV” mode are preserved.

CW related items:

REMEMBER: When in the MENU mode, CW timing and speed will

be disrupted! Remember this when adjusting parameters such as CW

speed and CW TX→RX delay!

• CW Keyer Mode - This selects from Iambic-B, Iambic-A and

Straight Key modes.

• CW Keyer Speed - This allows the adjustment of CW keyer speed,

when in Iambic mode, from 5 to 48 words per minute. This is the same

as the WPM item on the main display screen. While you may adjust

the CW speed while in menu mode, CW timing and speed will be

skewed until you exit menu mode!

• CW Sidetone Gain - This adjusts the sidetone volume in CW mode

as well as in the TUNE mode. This is the same as the STG item on the

main display screen.

• CW Side/Off Freq - This adjusts the CW sidetone and TX/RX offset

frequency in 10 Hz steps from 400 to 1000 Hz.

• It should be noted that the CW transmit carrier frequency is

always higher in frequency by this amount and it exactly

matches the sidetone frequency which is to say that if you match

the pitch of the other station's receive signal with the pitch of the

sidetone, both with be transmitting on the same frequency.

Ailunce HS1 User’s Manual

27

• When adjusting the sidetone, always take care to be sure that

the center frequency 300 Hz and/or 500 Hz filter that you use

matches the sidetone or else the stations that reply to you may do

so outside the filter's passband!

• Note that if this is turned ON, the “ring” contact of the paddle

jack is still the “PTT” line as before.

• This has no effect when “CW Keyer Mode” is set to “Straight

Key” mode.

• USB – The receiver operates in USB and the transmit

frequency is above the displayed frequency by the amount of the

configured sidetone frequency (e.g. menu parameter

“CW Side/Off Freq”). One must do some mental math to

calculate the actual transmit frequency.

• LSB – The receiver operates in LSB and the transmit frequency

is below the displayed frequency by the amount of the

configured sidetone frequency(e.g. menu parameter “CW

• CW Paddle Reverse - This swaps the Dit and Dah position of the

paddles.

• CW TX->RX Delay - This sets the Transmit-to-Receive turnaround

time. Note: If you experience a problem with the CW key “hanging”

occasionally during CW operation (e.g. it goes “dead” for a second or

two and then recovers) you may wish to increase this time slightly.

There may still be a lingering bug that may show up if the TX->RX

turnaround time is set too short, but it is believed that this has been

fixed.

• CW TX/RX Offset – This sets how the receiver offset and/or the

frequency display operates in CW mode according to the following

settings:

Side/Off Freq”). One must do some mental math to calculate the

actual transmit frequency.

• AUT USB/LSB – In this mode USB is selected >= 10 MHz and

LSB is selected below 10 MHz.

• USB DISP – The receiver operates in USB but the displayed

frequency shifted upwards by the amount of the configured

sidetone frequency. The displayed frequency is that of the transmit

frequency and it is the frequency of the received signal if it is tuned

to match the pitch of the sidetone.

• LSB DISP – The receiver operates in LSB but the displayed

frequency shifted downwards by the amount of the configured

sidetone frequency. The displayed frequency is that of the transmit

frequency and it is the frequency of the received signal if it is tuned

to match the pitch of the sidetone.

• AUTO DISP – In this mode USB DISP is selected >= 10 MHz

and LSB DISP is selected below 10 MHz.

• USB SHIFT – The receiver operates in USB. Compared to

normal USB for SSB operation, the receive frequency is shifted

down and the displayed frequency is shifted up by the amount of

the configured sidetone frequency which causes a CW note that

would be zero-beat in USB mode to be heard at the pitch of the

sidetone frequency. The displayed frequency is that of the transmit

frequency and it is the frequency of the received signal if it is tuned

to match the pitch of the sidetone.

• LSB SHIFT – The receiver operates in LSB. Compared to normal

LSB for SSB operation, the receive frequency is shifted up and the

displayed frequency is shifted down by the amount of the

configured sidetone frequency which causes a CW note that would

be zero-beat in LSB mode to be heard at the pitch of the sidetone

frequency. The displayed frequency is that of the transmit

Ailunce HS1 User’s Manual

28

frequency and it is the frequency of the received signal if it is

tuned to match the pitch of the sidetone.

• AUTO SHIFT – In this mode USB SHIFT is selected >= 10

MHz and LSB SHIFT is selected below 10 MHz

Comments on the various modes:

The “USB” and “LSB” modes are equivalent to those found on many older

transceivers such as the Drake TR-7 in which the transmit frequency was

shifted from the receive frequency. In these transceivers the actual transmit

frequency is calculated by adding/subtracting the known frequency offset

from the dial frequency.

The “USB DISP” and “LSB DISP” modes are equivalent to those found on

current transceivers such as the Yaesu FT-100, FT-817, FT-847 and FT-897

to name but a few with the “USB DISP” being equivalent to the “CW”

mode and “LSB DISP” the same as the “CW-R” mode. In these modes the

radio's frequency is not shifted, only the display is offset by an amount

equivalent to the sidetone frequency. The displayed frequency is the actual

carrier frequency of the transmitted signal and that of the received signal if

it is tuned so that its pitch matches that of the sidetone.

The “USB SHIFT”, “LSB SHIFT”, and “AUTO SHIFT” operate by

shifting both the local oscillator and the display by the amount of the

sidetone/offset of the transceiver. Compared to “USB” mode, the

display doesn't change at all, but a signal that was zero beat in USB/LSB

mode now becomes audible at the sidetone pitch when set to this mode. The

“AUTO SHIFT” mode is equivalent to the CW mode in many

current-production Icom transceivers.

TCXO Related items:

• TCXO Off/On/Stop - When set to OFF the TCXO is read every

second or so and the temperature is displayed, but the frequency is not

corrected based on the temperature. When set to ON,

temperature-related frequency corrections are applied to minimize

frequency drift. When set to STOP the temperature sensor is not

polled and “STOPPED” is displayed in lieu of the temperature. The

“STOP” setting may be used by those who experience the one-second

“TICK” sound on higher bands (e.g. 15 meters and up) who have not

performed the modification to prevent this. Note: If you experience

this “tick” sound be certain that you have enabled the “RX/TX Freq

Xlate” mode, preferably setting it to “RX LO LOW” before

resorting to disabling the TCXO function and losing

temperature/frequency control.

• TCXO Temp. (C/F) - This selects either Centigrade or Fahrenheit

display of the TCXO temperature.

Spectrum Scope related items:

• Spec. Scope 1/Speed - This selects the update rate of the spectrum

scope, or it may be set to OFF which disables the spectrum scope

entirely. The OFF setting may be used to reduce the “helicopter”

sound that may be heard under low-signal conditions. This has been

renamed to“1/Speed” as the lower number indicates a slower speed.

• Spec/Wfall Scope Filter - This adjusts the “smoothing” of the

spectrum scope and waterfall display. Note: If your board uses an

LCD with an SPI interface a smoothing setting of 1 or 2 is

recommended.

• Spec. Trace Colour - This sets the color of the spectrum trace.

• Note: The “helicopter” sound may be significantly reduced by

placing an insulated metal shield between the RF and UI boards.

Ailunce HS1 User’s Manual

29

• Spec. Grid Colour - This sets the color of the background grid of the

spectrum scope.

• Spec/Wfall Scale Colour - This sets the color of the frequency scale

along the bottom of the spectrum scope and waterfall display.

• Spec 2x magnify - When set to ON this changes the span of the

spectrum scope and waterfall display from its normal +/- 24 kHz to +/-

12kHz. It does not increase the resolution, but rather the thickness of

the lines are doubled. Note that in frequency translate mode, the

receive (dial) frequency is always placed in the center of the screen.

• Spec/Wfall AGC Adj. - This adjusts the AGC response rate of the

spectrum scope and waterfall display. The default setting of 10 yields

the same response as the previous “fixed” setting of earlier firmware.

• Spec Ampl. - This adjusts the number of dB per vertical division that

the displayed signal represents. The available settings are:

◦ 5dB

◦ 7.5dB

◦ 10dB

◦ 15dB

◦ 20dB

◦ 1S-Unit (6dB)

◦ 2S-Unit (12dB)

◦ 3S-Unit (18dB)

Note that while these settings are primarily for adjusting the vertical

scale of the Spectrum Scope, they also have an effect on the brightness

and contrast of the waterfall display. With the

approximately dynamic range of the visual spectrum display being 4

vertical graticules, atypically useful setting of this parameter is “10dB”

as this represents the typical range of signals found on an amateur band

under normal conditions.

It is recommend that you find the optimal setting for the spectrum

scope and then leave it there rather than adjust it for the waterfall

display, which has its own set of adjustments for brightness and

contrast!

• Spec/Wfall Ctr. Line – This is used to set the color of the vertical

grid line that coincides with the center frequency of the receiver on the

spectrum display and waterfall display to make the “center tuning”

frequency more obvious. When Frequency Translate is off, this will

be in the center, but if Frequency Translate is on, this will be to the

left and right of the center, depending on whether the mode is set to

“RX LO HIGH” or “RX LO LOW”, respectively. If “Magnify” mode

is on, this line will always be in the center.

• Scope/Waterfall – This parameter has two settings: SCOPE and

WFALL to select Spectrum Scope and Waterfall Display, respectively.

There is a “shortcut” to this setting: Pressing the “BAND-” and

“BAND+” buttons simultaneously will toggle between the two modes

– although this will have no effect if already in the MENU mode.

• Wfall Colour Scheme – This selects the color “palette” used to

represent the strength of the signals displayed on the waterfall display.

At present there are three palettes available:

◦ Grey – Weak signals are represented by black/very dark

colors with strong signals depicted by very light/white colors.

◦ HotCold – In this palette weak signals are represented by

dark blue signals with strong signals indicated by red colors.

◦ Rainbow – This palette represents weak signals with

blue/violet signals with progressively stronger signals

indicated as if colors of the rainbow with the red being the

strongest.

◦ Blue – This palette represents weak signal as dark blue,

progressing to pale blue as signal strengths increase.

Ailunce HS1 User’s Manual

30

◦ INVGrey – This is the “inverse” of the “Grey” palette in that

weak signals are light and strong signals are dark.

• Wfall Vert Step Size – This is the number of vertical pixel steps per

waterfall update. While the waterfall data is updated internally each

individual pixel, this allows the user to “skip” some internal updates

of that data to improve the update rate of the display – particularly if

one is using an LCD with an SPI interface. While no visual data is lost

by increasing this number, increasing the number too high can cause

the display to appear “jerky”. A value of “1” is the smoothest as the

screen is updated every time new spectral data is available and a value

of “2” looks quite smooth.

• Wfall Brightness – This adjusts the baseline brightness of the

waterfall display. A value of “100” represents zero with numbers

above this adding to brightness and those below it subtracting the

brightness. If the display is too dark, this value may be increased and

viceversa. This setting is used with “Wfall Contrast” to suit the user's

taste.

• Wfall Contrast – This multiplies the brightness value of the

waterfall display where a value of “100” equals 1.00. Increasing this

value makes brighter signals brighter and darker signals darker. This

setting is used with “Wfall Brightness” to suit the user's taste.

• Wfall 1/Speed – This adjusts the update rate of the waterfall, with a

higher number being a slower rate of update. If you are monitoring a

section of an amateur band for activity, you will likely not want a very

fast update rate or else activity on other frequencies may move up the

screen too quickly and be missed.

Note: If the speed is increased (number decreased) too much the

waterfall speed will increase very little, but the response of the

transceiver to button-presses and knob adjustments will become

sluggish. Such is indicated by color change of this adjustable

parameter from Yellow to Red as this effect will (likely) increase –

particularly if DSP is activated.

• Scope NoSig Adj. - This adjust how low or high the “no signal”

baseline will auto-adjust on the spectrum scope. A low number will

raise the baseline up while a high number will lower the baseline.

• Wfall NoSig Adj. - This adjust the background and overall

brightness of the spectrum scope. A “low” number will brighten the

scope while a “high” number will darken the scope. With the waterfall

display one may use the “Wfall Brightness” and “Wfall Contrast”

settings to adjust the brightness and contrast of the waterfall display to

suit your needs.

• Wfall Size - This sets the size of the Waterfall display: Normal =

The same size as the Spectrum Scope, Medium = Slightly larger,

without the banner at the top.

Configuration Menu:

The final item of the main menu item is “Configuration Menu”. When set to

ON the “Configuration” menu is enabled and its menu items are accessible.

General radio setup related items:

• Step Size Marker - When set to ON a line below the appropriate

digit of the main frequency display indicates the selected step size.

• Step Button Swap - When ON, the STEPM (Step-) and STEPP

(Step+) buttons are swapped. The intent of this is so that the position

of the Step Size Marker moves to the left/right in conjunction with

the left/right step size button when this setting is on.

• Band+/- Button Swap – When on, the BANDM (Band-) and

BANDP (Band+) buttons are swapped. This is provided for those

who wish to these buttons to be swapped – perhaps, because they also

Ailunce HS1 User’s Manual

31

have the STEP buttons swapped as well.

• Transmit Disable - When ON, all transmit functions are disabled.

This may also be toggled by pressing-and-holding the TUNE button.

An indication of Transmit Disable being active is the TUNE button's

text being displayed in grey.

• O/S Menu SW on TX - (“On-Screen Menu Switch on Transmit”)

When ON several of the receive-specific adjustments (“AFG” and

“RIT”) are switched to transmit-specific adjustments, such as “CMP”

and “MIC” or “LIN” in voice modes, respectively. This allows more

convenient access to these parameters when in transmit mode.

CW-related functions are not available in this manner.

• Mute Line Out TX – This enables/disables the muting of the LINE

OUT mode when in TX mode. The LINE OUT is always disabled

when “Frequency Translate” mode is active.

• TX Mute Delay – This causes the transmit audio to be muted for a

brief period after activating the PTT line with the settings depicted in

100ths of seconds. The range is from 0 (disabled) to 25 (250

milliseconds.) This may be used to suppress a “click” or “clunk”

produced by microphones when the transmitter is keyed, particularly

electret types that are powered up at the moment that the radio is

keyed.

• LCD Auto Blank – With settings of “Off” and adjustable from 5-15

seconds, this enables a feature in which the LCD backlight will

automatically blank after the configured number of seconds after a

button was pressed or knob turned when NOT in MENU mode. This

mode may be used to reduce power consumption – particularly when

the transceiver is being batterypowered. When the LCD backlight is

turned off, the spectrum scope and waterfall are are also disabled

(“frozen”, actually), reducing a potential noise source as well.

• Filter BW Display – This setting sets the colour of a line below

the Spectrum Scope or Waterfall display that graphically depicts both

the bandwidth and frequency span of the currently selected filter and

mode.

• Voltmeter Cal. - This setting is used to calibrate the on-screen

voltmeter. A setting of 100 (default) represents unity (1.00) with each

step representing approximately 0.1%.

• Max Volume - This sets the maximum permitted setting of the AFG

(“volume control”), setting the maximum “safe” level. This is most

useful to those who exclusively use headphones.

• Max RX Gain (0=Max) - This sets the “maximum” gain of the

receiver/AGC system. The default of “3” is a compromise of stability

in preventing feedback at normal volume levels with no antenna

connected. This setting can be used to prevent the receiver's gain from

getting too high under no-signal conditions, particularly if all of the

various modifications have not yet been done to prevent feedback. It is

recommended that this be set to the default of 3 when Frequency

Translate is active.

• Key Beep – When set to ON a short beep will be heard with key

presses. For “short” (pressand-release) button-pushes, the beep will

sound at the instant that the button is released. For “long”

(press-and-hold) button-pushes, the beep will sound as soon as the

time has elapsed for the press to be considered valid, at which point

the button may be released. (This does not disable the “CW Sidetone

reference” beep produced by button G3 – see below.)

• Beep Frequency – This sets the frequency of the key beep, in 25 Hz

steps.

Receiver related items:

Beep related items:

Ailunce HS1 User’s Manual

32

• Beep Volume – This adjusts the volume (loudness) of both the key

beep and the beep that is heard when button G3 is pressed and held (in

CW/LSB/USB modes) to generate a CW “reference” tone of the same

frequency as the CW transmit-receive offset/CW sidetone.

• CAT mode - This enables the CAT mode which is based on a USB

driver that allows remote control of the transceiver. This setting is

NOT saved in EEPROM. The CAT mode is in development and has

limited capabilities.

• Freq. Calibrate - This adjusts the frequency calibration of the

transceiver in Hz, referenced to 14.000 MHz. Please refer to the

section “Calibrating the HS1’s Operating Frequency” at the end of

this document.

CAT related items:

• NOTE: If you have the USB programming cable connected and

enter CAT mode, it is likely that the transceiver will crash! If you

have programmed the transceiver you must first disconnect the

transceiver for 10-15 seconds before reconnecting it and enabling

CAT mode.

• EEPROM save may not work reliably if CAT mode has been

enabled/disabled since the last power-up.

Frequency related items:

◦ Use the STEP- and STEP+ buttons - changing the step size as

necessary - when making this adjustment. Note that if the STEP

buttons are used, only up to 1 kHz step sizes will be selectable,

but if a larger step size was set prior to entering this menu

function, that step size will be used.

• Freq. Limit Disable – This enables the built-in frequency (tuning)

limits of 1.8-32 MHz, allowing one to tune the dial/display to

practically anything!

◦ NOTICE: This should be considered to be an experimental

feature and treated with care, considering the limits of the Si570,

the surrounding hardware and the tuning algorithm itself: There

are no guarantees that any of the hardware will work at all

outside the “normal” tuning range!If you enable this feature

and tune outside this range, note that the frequency will NOT be

saved with a power-off. Additionally, if you tune outside this

range and THEN turn OFF this feature, you will find that the

band that you were on from which you tuned outside the range

may be “locked out” until you re-enable this feature and tune

back down into a “valid” amateur band (e.g. 80-10 meters.)

Again, this feature is for EXPERIMENTATION ONLY. If it is

reported that it is useful, it and other, related features may be

integrated into the transceiver, later.

I/Q Gain and Phase related items:

Notes:

• Please read the procedure for calibration of the RX IQ gain and

phase balance for more detailed information. This procedure may be

found elsewhere in this document.

• You must be in the appropriate mode (e.g. LSB, USB, RX, TX) in

order to adjust the relevant item. If the item is available to be adjusted,

its parameter will be displayed in white.

• LSB RX IQ Bal. - This adjusts the IQ Gain balance in LSB RX

mode.

• LSB RX IQ Phase. - This adjusts the IQ Phase balance in LSB RX

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33

• USB/CW RX IQ Bal. - This adjusts the IQ Gain balance in

USB/CW RX mode.

• USB RX IQ Phase. - This adjusts the IQ Phase balance in USB RX

mode.

• AM RX IQ Bal. - This adjust the IQ Gain balance in AM RX mode.

• LSB TX IQ Bal. - This adjusts the IQ Gain balance in LSB TX

mode.

• LSB TX IQ Phase. - This adjusts the IQ Phase balance in LSB TX

mode.

• USB/CW TX IQ Bal. - This adjusts the IQ Gain balance in

USB/CW TX mode.

• USB TX IQ Phase. - This adjusts the IQ Phase balance in USB RTX

mode.

PA bias adjustment related items:

• CW PA Bias (If >0) - If this setting is greater than zero, it is sets the

applied PA bias during transmit when in CW mode. If this value is

zero the setting of “PA Bias” (see below) is used.

• PA Bias - This is the setting applied to the final transistors during

transmit. If the value of “CW PA Bias” is set to a value of zero, this

value is used during CW transmit.

• The signal gain of FET power transistors will vary with their

bias. If you set the PA bias in CW lower than that in SSB mode,

you can expect that the RF power output will be LOWER. The

converse will be true if the PA bias is set higher (e.g. higher

power

Note:

• It is not possible to enter CW transmit mode without RF drive being

present. If it is desired that the PA bias current be measured for CW

transmit, it is necessary that the bias first be set in SSB mode, NOT in

TUNE mode, by keying the PTT with no audio and then noting the

numerical value at the desired PA current. Once this value has been

obtained, it may be applied to the CW PA Bias setting.

Power/VSWR Meter related items:

• Disp. Pwr (mW) – When set to ON this enables the display of

forward and reflected RF power, in that order, in milliwatts in the

upper-left corner, just below the “RIT” and “WPM” displays and is

updated only when the transmitter is keyed. In order to remove these

numbers from the screen, set this to OFF and key the transmitter.

• Pwr. Det. Null – This nulls the forward and reverse power sensors

when no RF power is present. This setting is enabled ONLY when

“Disp. Pwr (mW)”, above, is enabled. This setting is to be adjusted

ONLY when the transmitter is keyed in SSB mode WITH NO

MICROPHONE CONNECTED and is just to the point that the

forward and/or reverse power indicators just flicker between 0 and 1

or 2.

◦ Note that this setting is NOT saved in EEPROM and is always

OFF upon power-up.

◦ Note: If the resistor-change modification to the SWR circuitry

has not been done you will not be able to “null” this out and you

will get a warning to this effect when you power-up the

transceiver.

• 80m Coupling Adj. - This adjust the calibration factor for the

forward and reverse power sensors when operating on 80 meters. If a

known-accurate wattmeter is available, use this adjustment with

“Disp. Pwr (mW)” enabled to accurately set the wattmeter for this

frequency range. A setting of 100 represents unity (1.00).

.

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The above offsets the display as follows:

5 Watt Power calibration items:

These are accessible ONLY if the transciever is set to the relevant
band AND the 5 watt setting:

• 40m Coupling Adj. - This adjust the calibration factor for the

forward and reverse power sensors when operating on 40 and 60

meters. If a known-accurate wattmeter is available, use this adjustment

with “Disp. Pwr (mW)” enabled to accurately set the wattmeter for

this frequency range. A setting of 100 represents unity (1.00).

• 20m Coupling Adj. - This adjust the calibration factor for the

forward and reverse power sensors when operating on 20 and 30

meters. If a known-accurate wattmeter is available, use this adjustment

with “Disp. Pwr (mW)” enabled to accurately set the wattmeter for

this frequency range. A setting of 100 represents unity (1.00).

• 15m Coupling Adj. - This adjust the calibration factor for the

forward and reverse power sensors when operating on 17, 15, 12 and

10 meters. If a known-accurate wattmeter is available, use this

adjustment with “Disp. Pwr (mW)” enabled to accurately set the

wattmeter for this frequency range. A setting of 100 represents unity

(1.00).

• FWD/REV ADC Swap - This swaps the A/D inputs of the forward

and reverse power detectors. This may be useful if the builder

reconfigures the FWR/REV coupler such that its detection sense is

reversed, such as by rewiring it back-to-front or changing the “sense”

of the windings. This may be done if the builder finds that the reverse

isolation of the unit's “Tandem” coupler is better when so-configured.

• XVTR Offs/Mult - This is a transverter multiplication factor that can

range from OFF to 1-10. When this parameter is set to something

other than OFF, the multiplication factor and the offset (below) is

applied and the digits of the main frequency are displayed in

YELLOW.

Transverter related items:

Note: When the transverter mode is active, 1 MHz and 10 MHz

frequency step sizes will be available for tuning the main frequency

dial.

• XVTR Offset (Hz) - This is the frequency offset that is applied to

the transverter multiplication factor. A frequency offset of up to

999.000 MHz may be “dialed” in. ◦ When this parameter is selected

within the menu system it is possible to use the STEP buttons to select

a step size of 1 and 10 MHz. When one navigates away from this

parameter in the menu and a 1 or 10 MHz step size is selected, a
smaller step size will automatically be forced.

Displayed Frequency = (Tuned Frequency * XVTR Mult )
+ XVTR Offset

• 80m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 60m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 40m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 30m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 20m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 17m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 15m 5W PWR Adjust - This adjusts the drive level so that 5 watts

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“FULL” Power calibration items:

These are accessible ONLY if the transciever is set to the relevant band

AND the FULL power setting:
may be obtained on this band.

• 12m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band.

• 10m 5W PWR Adjust - This adjusts the drive level so that 5 watts

may be obtained on this band

• If you see the settings for the 5 watt power adjust defaulting to

ZERO, first POWER OFF the radio using the POWER button to

initialize the memory-save locations.

• If you do not have the 5 watt mode AND the band to be adjusted

selected, the relevant parameter will be “oranged out” and you will not

be able to adjust it – this being done to prevent accidental adjustment

of the wrong parameter.

• The 2 watt, 1 watt and 0.5 watt levels are based on proportional

scaling of the 5 watt settings. • While you may get 5 watts in TUNE or

CW mode, your measured output power may be lower in SSB mode

owing to the peak-average nature of SSB. Unless you have a

peak-reading SSB power meter, do not trust it to properly read the

power output when in SSB! Also, remember that the adjustment of the

Mic Gain (or Line Gain) settings will affect your output power when

in SSB.

• NOTE that unless your final/driver amplifier is appropriately

modified, you may not be able to get full 5 watts on some of the

higher bands (e.g. 15 meters and above.) Please follow the discussions

on the Yahoo Group and check the “HS1 board modifications”

document for updates on this topic.

Important notes on the 5 watt power adjustment settings:

• 80m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 60m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 40m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 30m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 20m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 17m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 15m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 12m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• 10m FULL PWR Adjust - This adjusts the drive level so that “full”

linear power may be obtained on this band.

• If you see the settings for the “FULL” power adjust defaulting

to ZERO, first POWER

OFF the radio using the POWER button to initialize the

memory-save locations.

• If you do not have the FULL power mode AND the band to be

adjusted selected, the relevant parameter will be “oranged out” and

Important notes on the “FULL” power adjustment settings – PLEASE

READ CAREFULLY:

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36

you will not be able to adjust it – this being done to prevent

accidental adjustment of the wrong parameter.

• The “FULL” power setting has NO effect on any other power

setting.

• While you may note a certain power output in TUNE or CW mode,

your measured output power may be lower in SSB mode owing to the

peak-average nature of SSB. Unless you have a peak-reading SSB

power meter, do not trust it to properly read the power output when in

SSB! Also, remember that the adjustment of the Mic Gain (or Line

Gain) settings will affect your output power when in SSB.

• Note that “officially” the HS1 transceiver is just a 5 watt radio, but

work is being done to derive modifications to safely increase the

output power.

• It is recommended that you do NOT increase the output power

above 10 watts unless you have verified that you have provided

adequate heat sinking of the final power transistors.

• Because the gain of the circuitry decreases with increasing

frequency, you should expect that the maximum power will decrease

on the higher bands! This is not a malfunction, but the reality of

semiconductor physics!

• If the output power is set too high, nonlinearity may result, causing

key clicks on CW and “splatter” on SSB and/or AM, so please take

care when adjusting the “FULL” power parameters!

• Please follow the discussions on the Yahoo Group and check the

“HS1 board modifications” document for updates on the topic of

improving the power amplifier of this radio!

DSP NR BufLen – This is the length of the De-Correlation delay

buffer. In order for the DSP to tell a voice signal from noise, it must

DSP related items:

have a sample of each, but given the absence of a separate noise

source, we have to “simulate” one by delaying the original signal to

“decorrelate” it. If we delay it too little, it will resemble the voice too

much and be ineffective. If we increase the delay, we can improve the

performance but if we delay too much we end up with an “echo” type

effect and a sluggish response.

• This value must always be larger than “DSP NR FFT

NumTaps”, below. If this rule is violated, the number will

turn RED and DSP NR operation will become ineffective.

• DSP NR FFT NumTaps – This is the number of taps in the FIR

(filter) comprising the DSP noise reduction filter. A smaller number of

taps implies a more agile filter, but also one that is less accurate while

a larger number of taps is more precise and potentially slower to

respond: A more “precise” filter may also reduce the actual

performance in that the automatic calculation of the filter's parameters

– which are, by their nature, imprecise, may “miss the mark”. A

higher number will increase processor loading and slow the

user-interface response.

• This value must always be lower than “DSP NR BufLen”,

above. If this rule is violated, the number will turn RED and

DSP NR operation will become ineffective.

• DSP NR Post-AGC – This determines whether the DSP noise

reduction will take place before the audio filtering and AGC or after

the audio filtering and AGC. The net effect will be the same, but there

will be important differences as perceived by the user:

• “NO”: DSP Noise reduction takes place before

filtering/AGC – The operation of the DSP noise reduction will

affect the S-meter reading. Because the noise reduction occurs

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37

prior to the AGC, the “quieting” caused by the noise reduction

will be compensated by the AGC and the perceived “quieting”

effect caused by the noise reduction will be reduced. Note that

this can give the impression that the noise reduction is less

effective than it actually is!

• “YES”: DSP Noise reduction takes place after

filtering/AGC – This operation of the DSP noise reduction

does not affect the S-meter reading. If very “heavy” noise

reduction is occurring, this can cause the perceived audio level

to drop, requiring that one “rides” the volume control,

particularly if there are weaker signals, buried in the noise,

amongst strong – a situation that can exaggerate the volume

differences! Be careful if you are wearing headphones when

using this setting!

Comment: It is recommended that one make judicious use of the “RF

Gain” control (RFG) to reduce the receiver gain when using the DSP

– particularly if “DSP NR Post-AGC” is set to “NO” - to reduce the

amount of noise that is heard under “no signal” conditions.

• DSP Notch ConvRate – This adjusts the convergence factor (“mu”)

of the filter and will have an effect on how quickly it “attacks” a CW

note. Because of the nature of the filter, this parameter's effects aren't

as obvious as those of the “Strength” adjustment of the noise

reduction filter. The higher the number, the more quickly it will

“attack” and notch a tone that appears in the passband. It should be

noted that very high numbers (e.g. a configuration to “attack” a tone

very quickly) can also affect voice quality.

• DSP Notch BufLen – This is the length of the De-Correlation delay

buffer. In order for the DSP to tell a CW note from noise, it must have

a sample of each, but given the absence of a pristine noise source, we

can “simulate” one by delaying the original signal to “de-correlate”

it. If we delay it too little, it will resemble the original signal too

much and be ineffective and start to affect voice. If it is increased, the

notch becomes more accurate, but it can slow down and, for a

number of reasons, actually lose effectiveness.

• NB AGC T/C (<=Slow) – This is the time constant for the noise

blanker AGC and it may be adjusted in an effort to improve the

performance of the AGC. A lower value corresponds with a slower

AGC within the noise blanker algorithm.

• AM TX Audio Filter – When set to “ON” this will insert a “brick

wall” audio bandpass filter (275-2700 Hz, approx) in the audio

transmit path – the same filter that is used on SSB transmit. When set

to “OFF” this filter is bypassed, allowing audio to be passed below

100 Hz and somewhat above 3000 Hz, improving fidelity.

• SSB TX Audio Filter – When set to “ON” this will insert a “brick

wall” audio bandpass filter (275-2700 Hz, approx) in the audio

transmit path – the same filter that is used on SSB transmit. When set

to “OFF” this filter is bypassed, allowing audio to be passed below

100 Hz and somewhat above 3000 Hz, improving fidelity.

Noise Blanker related items:

IMPORTANT: While you are in the menu system and it is being displayed,

the noise blanker is always disabled, so you must exit the menu to note the

effect of that parameter!

Transmit audio related items:

◦ Note that while fidelity is improved when this filter is turned

off, “talk power” is reduced as more transmit energy is devoted

the parts of the voice that do not carry information.

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38

◦ Note that while fidelity is improved when this filter is turned

off, “talk power” is reduced as more transmit energy is devoted

the parts of the voice that do not carry information.

◦ If the SSB audio filter is disabled, PLEASE be considerate of

other users on the amateur bands as your signal will also be

“wider”, extending both above 2.7 kHz and also suffering

somewhat in opposite-sideband rejection to approximately 200

kHz.

FFT Spectrum Scope and Waterfall related items:

• FFT Windowing – The use of “FFT Windowing” - the

pre-processing of spectral data before display – can greatly improve

the visual performance of the Spectrum Scope and Waterfall display

by decreasing “bin leakage” (e.g. “sidelobe”) - that is, the tendency of

a signal (say, a carrier) to “leak” onto the display above and below the

displayed frequency.

The use of “FFT Windowing” - the pre-processing of spectral data

before display – can greatly improve the visual performance of the

Spectrum Scope and Waterfall display by decreasing “bin leakage”

(e.g. “sidelobe”) - that is, the tendency of a signal (say, a carrier) to

“leak” onto the display above and below the displayed frequency.

The default setting is “Blackman” which is quite good in making the

spectrum scope look sharper and preventing signals from “bleeding”

into each other, but most of these windowing functions take a degree

of processor time and can slightly slow the response to knobs and

buttons, particularly if the waterfall speed is increased to “Yellow” or

“Red” speeds.

The following windowing functions are available:

• Rectangular: This is the same as no window function and

results in rather poor visual performance, particularly in the

presence of strong signals amongst weak ones. This setting has

negligible processor load.

• Sine (a.k.a. “Cosine Window”): This is slightly narrower

than “Rectangular” but still fairly wide and causes minimal

processor loading.

• Bartlett (a.k.a. Fejér): A “Triangular” window – somewhat

better than “Rectangular” and minimal processor load.

• Welch (Parabolic): Comparable to Bartlett.

• Hann (Raised Cosine): Very good sidelobe rejection, but not

as narrow as Hamming or Blackman. This has higher processor

load than the previous functions.

• Hamming (Raised Cosine): Narrower than Hann, but not

quite as good sidelobe rejection.

• Blackman (Default): This is a good, general-purpose function

with about the same “narrowness” as Hamming but not quite as

good sidelobe rejection.

• Nuttall: Slightly wider than Blackman, comparable sidelobe

rejection. This has the highest processor loading of the available

functions.

It may be observed that with the “wide” window function

(Rectangular, Sine, Bartlett, Welch – in decreasing tendency) that

strong signals will tend to “smear” across the display.

In contrast, for the narrowest function (e.g. Hamming and Blackman)

these can cause some weaker signals to be a bit more difficult to see

as with wider, more spread-out energy of voice signals may not be

integrated into multiple FFT bins and may not be quite as visible.

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[End of menu configuration items]

DSP Noise Reduction parameters:

The DSP Notch filter is an “Automatic” notch filter that will immediately

“seek and destroy” any CW (continuous) carrier that it finds, but it should

have a minimal effect on the normal human voice. It is active in the

“NOTCH” and “NR+NOT” modes, but it is always disabled when in the

CW mode as it would make such operation impossible.

The function with the best sidelobe rejection is the Hann, but even

though it is wider than the Hamming or Blackman this can also cause

some weaker signals to become more difficult to see owing to its

excellent sidelobe rejection and the lack of strong spectral energy from

one particular bin leaking into adjacent bins and being “visually

integrated”.

In experimentation I have found that the Blackman is the most visually

appealing, offering a reasonable compromise between sidelobe

rejection, width, and overall “look”.

For more information than you ever wanted to know about FFT

Windowing, see the article:

http://en.wikipedia.org/wiki/Window_function

Notes about adjustment of DSP-related configuration values:

The DSP Noise Reduction is active in either the DSP NR or NR+NOT

mode and it performs noise reduction be detecting the coherent (e.g.

non-random) properties of the human voice and quickly adapting a filter to

pass those frequencies and blocking the other frequencies.

The “strength” of this filter may be adjusted using the menu item #10, “DSP

NR Strength” - but be very careful with this as it easy to go overboard with

this setting. If it is set too high, the artifacts caused by the noise reduction

(e.g. a “hollow” or “watery” sound) can be worse than the interference than

you are trying to remove!

The default setting is a good place to start, and carefully increase

experimentally on signals of varying quality to get a “feel” the effects.

It should be noted that “DSP NR BufLen” and “DSP NR FFT NumTaps”

will also interact with the efficacy of the “DSP NR Strength” setting,

sometimes making a particular “strength” setting weaker, sometimes making

it “stronger.

Again: Remember that the “DEFLT” button will restore the settings to

usable defaults!

DSP Automatic Notch Filter parameters:

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The notch filter operates within the signal path prior to the AGC and the

DSP NR operation, so a strong “tune up” signal will not cause the S-meter

to deflect when the notch filter is active, but note that the codec AGC is still

active and the receiver may still desense if this signal is very strong and

cause the lower half of the S-meter to flash red.

Also note that the presence of a strong carrier may also cause some

“intermodulation” distortion – both from mixing products within the

transceiver's analog circuitry, but also due to the dynamic limitations of the

A/D converter as well as artifacts in the mathematical calculations being

carried out in the SDR itself!

Note:

• The notch filter may be useful in AM mode to eliminate the “tweet”

that appears when tuned very close to the center frequency. If you are

listening to a shortwave broadcast station, note that the automatic

notch may occasionally “attack” music with interesting results!

Operation at very high NR “strength” settings (e.g. >= 35):

As the DSP “strength” setting is increased the rate of filter adaptation is

slowed down. While this can have the effect of make a filter “stronger” to a

degree by making it focus more strongly on the voice components rather

than the rapidly-changing noise, if this setting is increased too much it may

change too slowly to track different voices!

While the higher settings (e.g. >= 35 or so) may (or may not) be useful for

voice, they can be useful for narrowband signals that do not exhibit fast

changes, spectrally speaking – such as CW: The effects of very “strong”

DSP settings on CW signals can, under certain circumstances, be quite

striking!

With very high “strength” settings and the slow adaptation rate, one may

perceive that the filter may be “stuck”, but turning the DSP filter off and

then back on will “reset” it and cause it to re-train. If you are using the the

DSP NR filter at such high settings, it is worth experimenting with turning

it off and on to get a “feel” as to how the filters respond.

It should be noted that at very high DSP settings (>45) the DSP NR is more

susceptible to crashing when exposed to strong impulse noises: Refer the

the section about automatic and manual resetting of the DSP NR, below. At

these high settings the DSP may “crash” by producing a loud white noise

rather than go completely silent.

There are some known problems. The DSP (especially the noise

reduction) tends to crash occasionally:

• Occasionally, the receiver audio will suddenly cut out when in Noise

reduction and/or Notch mode. As of version 0.0.214 there is an

algorithm that automatically detects most of the situations when this

occurs and will reset the DSP. In the event that a crash is not

automatically detected, you may reset the DSP by turning it (the DSP)

off and on again by either pressing, or pressing-and-holding button G2.

Important Note:

If, when the a menu item is changed, it will be necessary to turn off the

transceiver using the POWER button to save the changes to the EEPROM.

Alternatively, button F1 may be pressed-and-held to cause a save of all

settings to occur.

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Approximate specifications of the HS1 transceiver:

The following specifications are for a transceiver that has been modified

according to the “hs1_board_modifications_xxxx” file that may be

found in the FILES section of the YAHOO HS1 Yahoo group.

Because this is a software-defined radio and due to ongoing

modifications/improvements of the software and hardware, the

specifications continue to improve!

• Receiver sensitivity for 10dB S/N, CCITT filtering, taken at 28.3

MHz:

• Frequency coverage: 80, 60, 40, 30, 20, 17, 15, 12 and 10 meter

amateur bands, transmit. Receive: 3.5-30 MHz nominal including

general coverage, 1.8-32 MHz at reduced specifications.

• Frequency Translation enabled: Better than -111 dBm (0.6uV)

in a 2.3 kHz bandwidth, better than -126 dBm (0.11uV) in a 300

Hz bandwidth

• Frequency Translation Disabled: Better than -108 dBm

(0.89uV) in a 2.3 kHz bandwidth, better than -120 dBm (0.22uV)

in a 300 Hz bandwidth

The above specifications are for a receiver on which the

published sensitivity modifications are performed.

◦ Note that the ability of the Si570 to tune the radio below 2.5

MHz is not guaranteed in its specifications, but most units have

enough range to tune just below 1.8 MHz.

• Spectral Display Modes:

◦ Spectrum Scope: This is a spectrum analyzer with the vertical

divisions representing userdefinable amplitude variations of 5, 7,

5, 10,15, 20, 1 S-Unit (6dB), 2 S-Units (12dB) or 3 S-Units).

The baseline (“reference level”) of the analyzer is automatically

adjusted so that the signals within the displayed passband

best-fit the dynamic range selected by the userselected

dB/division. A graticule along the bottom of the display

indicates the approximate frequency of the signal being

displayed over a width of +/- 24 kHz. (48 kHz total.)

◦ Waterfall Display: As with the spectrum scope, the frequency

is displayed along the “x” axis but the signal strength is implied

by the displayed color. The newest signals are displayed along

the bottom of the screen, but as new readings arrive, the

representations of the older signals are shifted upwards giving

an ephemeral time record of recent activity on

nearby frequencies. There are several options for color

“palettes” that range from simple grayscale to “cold-hot” to

“rainbow” to represent weak to strong signals.

◦ There is also a “Magnify” mode for both the Spectrum Scope

and Waterfall Display mode that provides 2x magnification,

reducing the visible spectral width to just +/- 12 kHz (24kHz

total.)

◦ Both the Spectrum Scope and Waterfall Display are very

highly configurable. It is possible to disable one or both spectral

display modes if desired.

• Large-signal handling capability: Continuous “Clip Warning”

occurs above approximately -28 dBm and actual A/D clipping and

distortion occurs at and above approximately -18 dBm for signals +/-

the local oscillator frequency and higher for signals outside this range.

• Transmitter power output: 5 Watts, typical, linear. Modifications

may be made to increase this: Follow the discussions in the Yahoo

group.

Ailunce HS1 User’s Manual

42

• Frequency stability: +/- 30 Hz at 14 MHz over the range of 10 to 35

C, ambient with the transceiver in the case or better with the TCXO

active. (It can be much better than this.)

• Available TX/RX modes in this firmware version: CW, USB,

LSB, AM (full-carrier, double-sideband) and FM. AM transmit and

FM transmit/receive capabilities are available ONLY if the “frequency

translate” is activated (highly recommended!)

◦ FM options: Carrier (ultrasonic) squelch, subaudible tone

encoding and decoding, tone burst (“whistle up”) generation,

“narrow” (+/-2.5 kHz) and “wide” (+/-5 kHz) deviation and the

selection of 7.2, 10, 12 or 15 kHz pre-detection receive

bandwidths.

◦ FM sensitivity for 12 dB SINAD, CCITT filtering:

▪ 7.2 kHz BW filter: -103.7 dBm (1.46uV) with 1 kHz tone

at +/-1.5 kHz

▪ 10 kHz BW filter: -102.1 dBm (1.75uV) with 1 kHz tone at

+/-1.5 kHz

▪ 10 kHz BW filter: -104.0 dBm (1.41uV) with 1 kHz tone at

+/- 3kHz

▪ 12 kHz BW filter: -102.7 dBm (1.63uV) with 1 kHz tone at

+/- 3kHz

▪ 15 kHz BW filter: -99dBm dBm (2.50uV) with 1 kHz tone

at +/- 3 kHz

• CW mode receive/transmit and frequency display details: Nine

modes of CW display/shifting are available to emulate the various

makes of radios and suit the user's taste, ranging from no shifting,

display-only shifting, display and LO shifting and manual or automatic

LSB/USB shifting.

• In CW mode “CW-L” or “CW-U”, is displayed depending on

whether LSB or USB is being used for reception.

• CW Speed range: 5-48 WPM.

• Available audio filter bandwidths in this firmware version: 300

Hz, 500 Hz, 1.8 kHz, 2.3 kHz, 3.6 kHz, with a “wide” filter of 5, 6, 7.5

or 10 kHz being selectable in all modes except FM, where the filtering

is done prior to demodulation as noted above. All filters are

softwaredefined and additional bandwidths could be made available.

• DSP Filtering Capability: Noise reduction and Automatic Notch

Filter with adjustable parameters. Notch filtering is disabled in CW

mode for (obvious reasons!) or when using a “wide” receive

bandwidth.

• S-Meter calibration: “Industry Standard” (IARU Region 1,

Technical recommendation R.1) Smeter calibration where S-9 =

-73dBm (50.2uV @ 50 ohms) with each “S” unit representing 6 dB.

Units above S-9 are in dB units, as noted. For more information on

this calibration system

see the article: http://en.wikipedia.org/wiki/S_meter

• External audio input/output connections: “Line In” and “Line

Out” audio ports, and a “PTT” (Push-to-Talk) are provided via 3.5mm

connectors to allow the connection to an external device. With these

connectors it is possible to interface with an external device (a

computer or tablet/smart phone) and operate “Sound Card” modes

with the HS1 such as SSTV, PSK31, WSPR and other analog/digital

modes.

• Line out signal levels: Nominal 1 volt peak-peak, maximum when

AGC is operating.

• Line in signal levels: Nominal 0.1-1.0 volt peak-peak, adjustable

using the “Line Input Gain” settings.

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43

The ALC (Automatic Level Control)

This module requires a bit of explanation, so please read the following

section very carefully!

• Transmit ALC type: Look-ahead gain compressor with both pre-set

and available “custom” settings.

• Operating voltage range:

◦ 16.0 volts maximum

◦ To 11.0 volts minimum for full transmit power

◦ To 9.5 volts for reduced transmit power

◦ As low as 6.5 volts, receive-only: Only very low transmit power

may be possible – distortion on peak audio (SSB, AM) may

occur.

• Current consumption:

◦ Receive:

◦ Unmodified, approx. 410mA on 40 meters and below at 13.0

volts, approx. 440 mA on 10 meters, minimum volume,

maximum display brightness.

◦ The selection of minimum display brightness can reduce this by

40-60mA.

◦ The modification to the PA drivers to switch off bias when not

in TX mode can reduce this by a further 30-60 mA.

◦ Power off: <5 mA if the PA driver bias modification is

performed. (If this modification is not performed it is

recommended that power be disconnected from the transceiver as

the PA driver transistors will be biased on even when the power

is turned off, causing 30-60 mA of standing current.)

Prior to the addition of the ALC the POWER adjustment on the HS1 was

somewhat irrelevant when in a voice mode as it only added effective

attenuation in the audio path. If one adjusted the audio to 5 watts PEP when

in the 5 watt mode, it was possible to switch to the 1 watt mode and readjust

the audio gain to again achieve 5 watts as there was nothing within the code

to set levels!

What is more significant is that there was nothing in the code to prevent the

overdriving of the final amplifier stage, even if it had been set up properly

for a “clean” 5 watts as there was no way to be sure, without using an

external RF power meter, that the transmitter audio drive was properly set.

This was been changed in version code 0.0.207: It is no longer possible to

obtain a higher PEP power at a given power setting than a steady

carrier in CW or TUNE mode! Unless you have a true peak-reading RF

power meter, you will read a lower RF output power in SSB mode than

in CW mode.

Please re-read the above paragraph at least once to be sure that you

understand it!

How the ALC works:

All modern SSB transceivers have a form of ALC which monitors the

transmit power level and if it exceeds the set power level, it is cut back to

prevent overdriving of the finals. In this way the maximum output power

may be set for a mode that has intrinsically varying power levels.

Ailunce HS1 User’s Manual

44

With the ALC the PEP power from the transmitter should not exceed

the carrier level observed in TUNE mode, no matter the audio drive

level.

In order for the ALC to work there must be at least a minimum audio level

to drive it and to provide for this the F2 button has been repurposed to

change the (former) SWR meter to one of three modes:

• The SWR meter. This dynamically measures the forward and

reflected RF power, calculates the VSWR and displays it.

• The AUDio meter. This shows the audio level from -20dB to +12dB,

with 0 dB being “nominal”. It is acceptable for audio to occasionally

peak at +6 to +10dB.

Adjusting for the proper audio level when in SSB transmit mode:

• Speak normally if using the Microphone input, or set the nominal

input level if you are using the LINE Input mode.

• Use button F2 to select the AUDio meter.

• Use button M1 (below ENC1, the left-hand encoder) to select the on

screen CMP setting and use that encoder to adjust it to a setting of 1.

• Use button M3 (below ENC3, the right-hand encoder) to select the

on-screen MIC (or LIN) setting and use that encoder to adjust it, or you

may go into the Menu mode and adjust the “Mic Input Gain” (or “Line

Input Gain” as appropriate).

• While speaking normally, adjust the gain so that the audio meter peaks

up to “0” (zero) to +6 on the audio meter. It is fine for it to occasionally

peak higher than this.

• Now use button F2 to select the ALC meter.

• Use button M1 (below ENC1, the left-hand encoder) to select the on

screen CMP setting and use that encoder to adjust it, or you may go

into the Menu mode and adjust the “TX Compress Level”.

• Adjust this setting for an upwards indication of the ALC indicator.

See below for a discussion of this setting.

Using the ALC to control transmit power, or as a speech processor:

There are two ways to adjust the speech processor/compressor settings:

• Using the “CMP” numerical settings (which is the same as the “TX

Audio Compress” menu parameter)

• Setting the “CMP” (or the “TX Audio Compress”) setting to “SV”

and independently adjusting the “ALC Release Time” and “TX PRE

ALC Gain” settings.

Using numerical settings for CMP:

When using the numerical settings for the CMP setting (also the “TX Audio

Compress” parameter) the “ALC Release Time” and “TX PRE ALC

Gain” settings are automatically adjusted to provide “compression” settings

that become “stronger” with an increasing number.

“Manually” adjusting parameters when “CMP” is set to “SV”:

When the “CMP” (or the “TX Audio Compress” parameter) are set to

“SV” the parameters “ALC Release Time” and “TX PRE ALC Gain” may

be manually adjusted as desired to provide a custom compressor setting.

This ALC system has been designed to be flexible and be usable both as a

“standard” ALC used to set the SSB transmit power and as a

highly-effective compressor-type speech processor. To operate the the ALC

in this way requires attention to two separate parameters as described below.

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45

SSB operation with minimal speech compression:

• Set the Microphone/Line gain as described in the previous section

(e.g. around “0” on the AUDio meter with occasional peaks to +6 to

+10.)

• In the menu system, set the parameter ALC Release Time to the

default setting of 10.

• While speaking normally adjust the TX PRE ALC Gain parameter

for a peak reading on the ALC meter of 4-6 dB.

• Setting ALC Release Time to a higher value will reduce the

compression even more.

SSB operation with maximum speech compression:

• Set the Microphone/Line gain as described in the previous section

(e.g. around “0” on the AUDio meter with occasional peaks to +6 to

+10.)

• In the menu system, set the parameter ALC Release Time to the

default setting of 3 or lower.

• While speaking normally, adjust the TX PRE ALC Gain parameter

for a peak reading on the ALC meter of 8-16 dB.

• Setting ALC Release Time to a lower value and the TX PRE ALC

Gain to a higher value will increase the compression even more.

Explanation of the parameters and meters:

• Mic Input Gain/Line Input Gain: These operate directly on the

microphone and line inputs in the way that you would expect. These

parameters display as MIC or LIN on the main display, respectively.

• Audio meter: This displays the audio level, in deciBels, on the

selected audio input, with “0” being the level that will just achieve

100% power at the bottom of the ALC threshold. The level displayed

is NOT filtered in any way and signals outside the frequency range that

would be transmitted (e.g. <200 Hz, >3500 Hz) will register.

• TX PRE ALC Gain: This is a variable audio gain after audio filtering

in the transmit bandpass, after the audio metering, above, but before the

ALC circuit.

• ALC Meter: This indicates the amount of gain reduction in deciBels

that the ALC is providing to the audio path. The ALC is in the audio

path after transmit audio filtering so it will not respond to audio that is

outside the frequency range that will be transmitted. The ALC can only

reduce gain (by up to 40 dB) but it can never increase it and it will

settle to unity under nosignal conditions. Note that the ALC meter's

response is indicative of the ALC release time – see below.

• ALC Release Time: This sets the time, after audio has dropped below

the current threshold, that the ALC will take to release and reduce

attenuation. When set to the default setting of 10, the ALC will have

only a modest effect on the transmitted audio, taking several seconds for

the ALC to completely recover from a voice peak while setting it to the

maximum value if 20, the effect is almost that of disabling the ALC

entirely in terms of added compression in that the gain recovery rate is

approximately 1dB/second. Low values (below 5) will “follow” audio

very quickly and offer effectively very high compression rate.

Warnings:

• Do not set the Mic/Line gain such that the peak audio level on the

AUDio meter regularly peaks much above 4 to 8B, although occasional

peaks to +10 are fine. Avoid settings that “peg” the meter as this could

result clipping and audio distortion.

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46

• If the RF amplifier is working properly and not being overdriven,

input audio clipping should not cause “splattering” on the transmitted

signal, only “bad” sounding audio.

• Frequent, very high indications on the ALC meter (e.g. >12dB) can

cause annoying “pumping” of background noise on transmit audio,

which is to say that during periods of silence in the voice, sounds in

the background may rise up and become an annoyance to those

listening to the transmission on the air. A “fast” ALC release time (e.g.

low number) can make this effect worse.

• The use of a speech compressor/processor can significantly increase

the heat dissipation of the final transistors: Please be aware of this

while transmitting, making sure that your finals are adequately

heat-sinked!

• If the HS1 is being operated from lower than normal supply voltage

the RF amplifier may be unable to output a normal amount of power.

In severe cases, operating under these conditions may result in

distortion and/or “splattering” which can cause interference on the

• If operating at “FULL” power, splattering may result unless you had

carefully adjusted the “FULL Power” configuration settings such that

the obtained power level was within the linear range.

• If the “FULL” power setting was simply adjusted for

maximum power output you may expect that transmissions at

this power setting may sound somewhat distorted and could

cause a degree of “splattering”.

SSB operation and proper adjustment of the “5W PWR Adjust” and

“FULL PWR Adjust” parameters”:

If you get reports of “splattering” when you operate on SSB, first check the

AUDio meter to make sure that it is not “buried” in the red, then check the

ALC meter to verify that the CMP (“TX Compress Level”) is not set such

that this meter indicates excessive deflection in the red zone (e.g.

continuous excursions above 12-16dB). If you have appropriately adjusted

the microphone/line and ALC settings, but are still getting reports of

splattering, do the following:

• If you are on “FULL” power, set the power to 5 Watts.

• If you are running 5 Watts, set the power to a lower setting.

• If you are still getting reports of splattering, verify that the PA Bias is

properly set.

If reducing power “cleans up” the splattering problem, your final power

amplifier may not be able to output the expected amount of power on the

current amateur band and this could be for a number of reasons:

• The power supply voltage is low. If you are operating the radio on a

voltage lower than 12.5 volts, it may not be able to output power level

that you request so a lower power level should be selected if you

operate at that voltage.

• There may be a problem with the low-pass filter on that band. You

should compare the output power on that band with that of other bands

and if it is markedly lower, re-check – and readjust, if necessary – the

values of the toroidal inductors in that band's low-pass filters.

• If you get reports of splatter on “FULL” power but not on other

power settings, you should reduce the “FULL PWR Adjust” for that

band in the “Adjustment Menu” for that band, or remember to not

operate SSB at the “FULL” power setting. Remember: It is possible to

get quite a bit of RF output from the final transistors, but if it is Linear

and “clean” power that you want – necessary for SSB operation – you

Ailunce HS1 User’s Manual

47

will need to operate at a lower power than this “maximum” output!

• If the PA Bias was never set properly your RF amplier, nonlinear

operation may result. In order to set the PA Bias do the following steps:

• Adjust the radio's power supply for 12.5-14.0 volts.

• Insert an ammeter so that you can measure its current

consumption. This meter should be capable of reading up to 3

amps with a resolution of better than 0.1 amps.

• Connect the radio to a dummy load.

• Turn on the radio and select USB or LSB.

• Go to the adjustment menu and set the PA Bias to 0 (zero).

• Key the radio with no audio and note the current.

• With the radio keyed, adjust the PA Bias so that the current

increases by the desired bias current: Up to 0.5 amps is suggested,

although as low as 0.1 amps is adequate for linearity if you obtain

the desired amount of RF output power on all bands.

• Unkey the radio.

• Use the POWER button (or press-and-hold the MENU button) to

save the new PA Bias setting.

REMEMBER:

If your RF power meter does not have a good "Peak" reading function

specifically designed to read

PEP on SSB signals (many do not!) it will always give a false "low" power

reading on SSB, which is to

say that your power on voice peaks may be where it should be, but your

meter will be reading a much

lower pseudo-average!

As of firmware version 0.0.217 there is the ability to enable “Frequency

Translation” which mathematically shifts the center frequency by + or – 6

kHz, depending on the setting of menu item “RX/TX Freq Xlate”. This

function solves the problem of the “Zero Hertz” hole that would otherwise

cause a nulling of the AM carrier if the receiver were tuned such that it were

placed in the center of the receiver's passband. For more information on

this problem, see the information later in this section.

If “RX/TX Freq Xlate” is enabled, there are no special considerations that

need to be taken when tuning an AM signal other than those noted in the

section below regarding the narrow AM filtering.

Note: When offset-tuning and AM signal using the wide bandwidth filter

mode with frequency translate mode active, it is possible, when off-tuning

by 6 kHz to place the AM carrier in the “Zero Hertz” hole, resulting in

distortion of the received signal.

Tuning AM signals with wide and narrow filtering:

The AM bandwidth filtering operates as follows. The bandwidths noted

below are always available in AM, regardless of menu settings:

There is one “wide” bandwidth and several different bandwidths are

available for this setting:

Amplitude Modulation (AM) mode reception and transmission:

• 10 kHz: Pre-detection bandwidth: +/-10kHz (20 kHz total);

Post-detection bandwidth: 10 kHz.

• 7.5 kHz: Pre-detection bandwidth: +/-7.5kHz (15 kHz total);

Post-detection bandwidth: 10 kHz.

• 6 kHz: Pre-detection bandwidth: +/-6kHz (12 kHz total);

Post-detection bandwidth: 10 kHz.

• 5 kHz: Pre-detection bandwidth: +/-5kHz (10 kHz total);

Post-detection bandwidth: 10 kHz.

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48

Other (“non-wide”) bandwidths are available:

• 3.6 kHz: Pre-detection bandwidth: +/-3.6 kHz (7.2 kHz total);

Post-detection bandwidth: 3.6 kHz.

• 2.3 kHz: Pre-detection bandwidth: +/-2.0 kHz (4.0 kHz total);

Post-detection bandwidth: 2.3 kHz (300-2600Hz, adjustable).

• 1.8 kHz: Pre-detection bandwidth: +/-2.0 kHz (4.0 kHz total);

Post-detection bandwidth: 1.8 kHz (500-2300Hz, adjustable).

Some explanation is required for the 1.8 kHz and 2.3 kHz modes as you'll

note that the pre-detection bandwidth appears to be a bit on the narrow side

to accommodate the sidebands that extend out beyond the filter (e.g. greater

than the +/-2kHz bandwidth). If one tunes the receiver to the center

frequency of the AM signal when these bandwidths are enabled the audio

response will be limited to just 2 kHz by the pre-detection filter. If one

off-tunes from the center frequency, this +/- 2 kHz bandwidth – which

encompasses 4 kHz - may be shifted to include the higher audio frequencies

of one or the other sidebands of the AM signal.

Because it is always necessary to off-center tune an AM signal to obtain the

full audio bandwidth permitted by the 1.8 kHz or 2.3 kHz post-detection

filter, one of the two sidebands (upper or lower) may be encompassed in the

narrower bandwidth. This “quirk” may also be used to advantage in the

presence of QRM (interference) by selectively tuning for one sideband or

the other, moving away from the source of the interference.

How the AM demodulation in version 0.0.208 and later is different from

that in earlier versions:

In versions prior, the pre-demodulation bandwidth was fixed at 10 kHz,

which meant that all signals within +/10kHz would hit the demodulator.

Because the demodulator is, by its nature, a non-linear “device” it would

mix and cause distortion should any other signal within that +/-10kHz

passband also be intercepted. The selectable audio filter was applied after

the demodulation, but if there was an extraneous signal within the +/-10kHz

passband, the damage was already done!

In this version the filtering when in AM mode has been re-done: The Hilbert

transformers, which have a bandpass response, are replaced with low-pass

filters (e.g. response down to DC) that have their lowpass cut-off frequency

selected according to the desired bandwidth. Post-detection, there is

The “Zero-Hertz” hole problem if using firmware earlier than 0.0.217

or you are using firmware 0.0.217 with “Frequency Translation”

disabled:

This (and all “sound-card”) type SDRs have a “hole” at zero Hertz – right in

the middle of the display. This is the inevitable result of AC coupling to the

A/D converter (codec) and cannot easily be helped without added design

complication.

What this means is that if you tune in an AM signal “dead center” its carrier

will fall into this “hole” and disappear which effectively turns it into a

double sideband with no carrier – which is to say, it is no longer AM! If an

AM signal is tuned dead-center, it will sound terribly distorted – much

like an SSB signal tuned on an AM receiver!

The cure for this is simple: Do NOT tune the AM signal so that the

carrier is “dead center”. It is necessary only to offset-tune by a few

hundred Hertz, but it is necessary to do this!

Known issues with AM demodulation if using firmware earlier than

0.0.217 or you are using firmware 0.0.217 with “Frequency

Translation” disabled:

• Remember: AM signals must be off-tuned to avoid placing the

carrier in the dead center! An offset of a few hundred Hz is typically

Ailunce HS1 User ’s Manual

49

adequate.

• There is a known issue in which a weak heterodyne (“tweet”) can be

heard at frequencies close to the center frequency. This is caused by the

inexact 90 degree phase shift and slight amplitude imbalance in the

receive system: For the time-being, off-tune the carrier until it

disappears or you may try turning on the DSP notch filter, and you

should adjust the parameter “AM RX IQ Bal.” to minimize it.

Comments on adjusting the AM RX IQ Balance:

This adjusts the receiver I/Q amplitude balance when in AM mode and is

used to minimize the lowlevel “tweet” (e.g. tone) that may be heard when an

AM signal is tuned in slightly off center frequency. To null this tone it is

recommended that you tune in a strong carrier, offset it by 500 Hz and then

adjust this parameter to minimize the amplitude of this tone.

This adjustment is unlikely to completely eliminate this “tweet”, but it can

significantly reduce it. Note also that the efficacy of this reduction changes

with audio frequency in that the optimal null for a 400 Hz “tweet” tone (e.g.

200 Hz offset from the carrier frequency) will be different from that of a

1000 Hz “tweet” tone.

A recommended modification for HS1 Board version 0.4 (and possibly

earlier) if you are interested in AM reception:

As noted in the modification file it is recommended that capacitors C71 and

C73 (on the outputs of U16 of the RF board) be removed and replaced with

jumpers or zero-ohm resistors: Their DC-blocking function is provided by

capacitors C26 and C31 on the UI board and the removal of C71 and C73

will extend the low-frequency response of the receiver and reduce the width

of this “hole” significantly. It also has the side-effect of potentially

improving the low-frequency opposite sideband rejection as it is one-fewer

component in the audio path to have its value change with temperature and

cause a phase/amplitude shift.

AM Transmission:

AM transmission is possible ONLY when frequency translation mode is

active!

When transmitting using AM, the power level will automatically be set to 2

watts to prevent the PEP from exceeding the maximum “clean” power level

available. If one does not transmit, the power level will not be automatically

changed.

If an attempt is made to transmit with frequency translation mode turned

off, the transmitter will key, but there will no transmit out power at all in

AM mode!

There is no “TUNE” mode in AM mode!

You should remember several things about AM:

• It is MUCH less efficient than SSB! You will have a 9 dB reduction

(1/8th) of the “talk” power of SSB: That's just the way it is!

• The UNMODULATED resting carrier will be 25% of that of the

peak power! This means that if you are used to getting 5 watts peak on

SSB, you will get only 1.25 watts when no audio is present: Sorry

about that, but that's just the laws of physics!

The speech processor works in AM mode in exactly the same way that it

does in SSB mode and it should NOT be possible to exceed 100%

modulation.

There is presently ONE option for AM transmit mode: In the configuration

menu, the item labeled “AM TX Audio Filter” has the selection of ON and

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50

OFF. If it is “ON” (default) the transmit audio will be “brick-wall” filtered

from about 275 to 2700 Hz in the same way that the SSB audio is.

If this selection is set to “OFF” the audio filter is disabled. This has the

effect of increasing the fidelity of the audio – mostly through additional

low-frequency components (down below 100 Hz) and somewhat above 3000

Hz. While this can increase the audio fidelity on transmit, you should be

aware that it can significantly shift the RF energy from the audio spectrum

that contains speech intelligence and reduce the “talk power”.

Frequency Modulation (FM) mode reception and transmission:

IMPORTANT:

• As of this firmware version the FM mode is new and is disabled

by default.

• Expect there to be bugs and “rough edges”!

• Your mileage may vary, so there!

• The noise blanker and DSP noise reduction and notch are

disabled in FM mode

WARNING:

• Transmitting on FM means that a continuous carrier is being

generated. Be absolutely certain that the final transistors on the

HS1 are adequately heat-sinked and do not get too hot and also

that your power supply is capable of the current being drawn.

• It is recommended that the lowest transmit power be used on

FM that will achieve a “full quieting” signal for the receiving

station's (or repeater's) receiver.

FM (Frequency) modulation is now available experimentally on the HS1

and while it is believed to work properly, it likely has a few “issues.”

Repeater operation is possible if one uses the “SPLIT” mode and sets

the receive and transmit frequencies in separate VFOs. By “swapping”

the VFOs, one can effect a “reverse” function and listen on the input

frequency while transmitting on the output – useful for checking for a

simplex path.

The “FM” produced by the HS1 is compatible with PM, which is to say that

for modulation, a 6dB/octave preemphasis is applied and a 6dB/octave

de-emphasis is done on receive audio: This is the worldwide standard

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51

for narrowband frequency modulation on amateur and commercial

frequencies.

To enable FM:

• You MUST have Frequency Translate enabled: It will not work

without it!

• Set the menu item “FM Mode Enable” to ON.

When in FM mode, the “RFG” control becomes “SQL” (Squelch) – also

operated by ENC2. The higher the number, the “tighter” the squelch and a

setting of “0” unconditionally opens the squelch. You will note that when

the squelch opens, the “FM” on the mode indicator will change color: More

on this later.

Two “modes” of FM are available: The default is “Narrow” with +/- 2.5 kHz

peak deviation (w/1kHz modulation) and “”Wide” with +/- 5 kHz peak

deviation, the former being commonly used on HF and the latter being that

which is used on VHF bands except for those instances where the “narrow”

(+/- 2.5 kHz) mode is specifically used by local option.

These two modes are more or less interoperable, with the following

provisions:

• Operation of “Wide” (+/-5kHz) on “Narrow” frequencies will result

in “loud” audio, possible “squelch clamping” and splattering onto

adjacent “narrow-spaced” channels.

• Operation of “Narrow” (+/-2.5kHz) on “Wide” frequencies will

result in chronically “low” audio, reduced “copyability” under

weak-signal (noisy) conditions and everyone telling you to talk

louder!

There is also a selection of receiver bandwidths:

• 7.2 kHz – This is suitable only for “Narrow” operation and even this

will result in a bit of added distortion as the filter about as narrow as it

may be to pass audio. Using this setting the weak-signal sensitivity is

the highest amongst the FM filter bandwidth settings since this

narrowest filter also intercepts less noise under weak-signal

conditions.

• 10 kHz – This is the “default” bandwidth and is suitable for

“Narrow” bandwidth and while it will work for “Wide” bandwidth,

slight distortion may occur on voice peaks.

• 12 kHz – This is wider than necessary for “narrow” bandwidth and is

recommended for “Wide” bandwidth.

Subaudible tone generation:

The menu item “FM Sub Tone Gen” enables and sets the frequency for

subaudible tone generation. All common frequencies (including NATO and

some strange ones) are included and when set to something other than OFF,

the tone is modulated on the carrier during transmit.

The tone deviation in “Narrow” mode is approximately +/- 300 Hz and

around +/- 600 Hz in “Wide” mode.

Subaudible tone detection:

Also known as “Tone Squelch” this is enabled by setting the menu item

“FM Sub Tone Det” to something other than “Off”. When it is activated, it

is required that BOTH the squelch be open AND the tone be detected.

Comment:

Subaudible tone detection, particularly in the presence of noise, is rather

difficult. If the tone detection drops in and out on weak signals you may

wish to turn it off.

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Tone Burst generation:

Although it is getting rarer, some repeaters may still require “tone burst”

and this is enabled by setting the menu item “FM Tone Burst” to something

other than “Off”. Two tone frequencies are currently provided: 1750 Hz and

2135 Hz. The duration of the tone is 1 second.

To transmit a tone burst:

• Key the transmitter. (It must be in FM mode)

• While the transmitter is keyed Press-and-Hold button G4, the “Bandwidth

Change” button.

• While a tone burst is being generated the “FM” on the mode indicator

changes to a yellow background.

Squelch/Tone decode indications:

The “FM” mode indicator changes according to the squelch and tone

detection status:

• “FM” on dark blue background – Squelch closed (and tone

decoder not decoding).

• “FM” on light background – Squelch open.

• “FM” on red background – This is displayed if the tone decoder is

detecting a tone: Audio will be heard.

◦ If tone decoding is not active, audio will be heard.

◦ If tone decode is active, audio will not be heard, but this

indicates that a signal is present (or the squelch is loose) but does

not match the tone decode setting.

Additional comments:

• The audio (speech) processor is active on FM, but owing to the nature of

FM communications (e.g. low noise with good signals) “strong”

compressor settings will likely result in audio that sounds vary “processed.”

Lower settings (e.g. “2”) are recommended when using FM.

• The squelch range is a bit “compressed” - that is, a there is not much

difference in the low number range for squelch adjustment (for weak/noisy

signals) but only a small range for those that are nearly full quieting. It is

possible that at the maximum squelch setting that it will "clamp" on audio

peaks or may even fail to open at all, in which case one should reduce the

setting.

• The tone decoding is a bit slow to respond, particularly on the “release”

when a tone disappears – in which case a properly-set squelch will close the

audio gate. This is an artifact of the need for narrow bandwidth detection,

the need to validate the tone detection to prevent it from “bouncing” and

also the limited amount of processing power available to do the tone

decoder processing.

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Before you get on the air -

Initial set-up of the HS1 transceiver:

• Be certain that you have reviewed the “HS1 board modification”

file. This document details various modifications that will improve

performance of the HS1 and prevent problems.

• Carefully observe the start-up screen: If you see warnings –

typically in red – pay close attention to and resolve them – some of

which are detailed in this section.

• Turn on the “Frequency Translate” mode. This does not default to

“ON”, but there is a warning that is displayed on power-up if it is not

activated. Be certain that the adjustment menu (yellow) parameter

“RX/TX Freq Xlate” is set to “RX LO LOW”.

• PA Bias setting: Before RF output may be obtained, the PA bias must

be properly set as follows:

◦ DO NOT PERFORM THIS STEP UNLESS THE RF OUTPUT

TRANSISTORS ARE PROPERLY HEAT-SINKED!

◦ Connect an ammeter in series with the HS1 power supply. This

should be capable of 3 amps with better than 0.1 amp resolution.

◦ Connect a known-good dummy load to the HS1.

◦ Set the HS1 to 10 meters and the mode to LSB or USB.

◦ Go to the Calibration menu item “PA Bias”.

◦ With NO AUDIO present (e.g. minimum microphone gain and

quiet room) key the transmitter: QUICKLY set the bias to ZERO –

this may be done by pressing the DEFLT button (F2). Note the

current reading on the ammeter.

◦ With the transmitter still keyed, increase the PA Bias setting so that

there is a 0.5 amp increase in the current reading on the ammeter,

which should correspond with 0.25 amps per RF output transistor.

Once you have obtained this, unkey the transmitter.

◦ Press-and-hold F1 to save the setting to EEPROM.

◦ Important notes:

▪ Depending on the RF drive level and transistor gain, the bias

setting may need to be adjusted slightly: The more bias, the

higher the gain and vice-versa. You should not need more than

1 amp, hopefully!

▪ The “CW PA Bias” adjustment is specifically for CW

operations and is described earlier in this manual.

• Band-Gain adjustments: This sets up the transmitter gain on a

per-band basis according to the following procedure:

◦ DO NOT PERFORM THIS PROCEDURE UNLESS THE RF

OUTPUT TRANSISTORS ARE PROPERLY HEAT-SINKED!

◦ If you have already verified that the HS1's built-in wattmeter is

properly calibrated, you may use it for the following steps. If you do

so, set the parameter “Disp. Pwr (mW)” to ON to display the

transmitted power in MILLIWATTS (e.g. watts * 1000).

◦ Connect a power supply capable of at least 3 amps while

supplying between 12 and 14 volts.

◦ Connected a known-good wattmeter and dummy load.

◦ Set the transmitter to CW mode.

◦ Set the band to 80 meters.

◦ Set the power to 5 watts.

◦ Go to calibration menu item “80m 5W PWR Adjust”.

◦ Press the TUNE button to enter transmit, a tone should sound in

the speaker: The number to the right of the “80m 5W PWR

Adjust” should turn white.

▪ If the number does not turn white, press TUNE again to

return to receive mode and verify the band and 5 watt power

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◦ Adjust the parameter for “80m 5W PWR Adjust” upwards and

note if you get at least 7 watts. If you do, adjust this setting for 5.0

watts output on your external RF wattmeter.

▪ If you are NOT able to obtain at least 7 watts on the band you

will not be able to obtain a “clean” 5 watts on SSB, either! It is

recommended that the final power setting be no higher than

approximately 75% of the maximum, saturated power

obtained! Failure to do this downward power adjustment will

likely result in clipping/splattering on SSB/AM voice peaks

on that band!

◦ WRITE DOWN the setting obtained for each band.

◦ Press the TUNE button to return to receive.

◦ Repeat the above steps for each band.

◦ Once the “5W PWR Adjust” settings are obtained, set the HS1's

power setting to FULL, the band to 80 meters, and go to the “80m

Full PWR Adjust” setting.

◦ Press TUNE to go to transmit.

◦ Increase the setting and note the maximum power setting – then

press TUNE again to stop transmit, going back to receive.

◦ Calculate the power level that is 75% of the reading you obtained

in the step above and write this number down for that band.

▪ WARNING: Failure to set this at 75% power (e.g. below

saturated) will likely result in clipping/splattering on SSB/AM

voice peaks on that band!

◦ Press TUNE again and adjust the setting to obtain the calculated

power.

◦ Press TUNE again to stop transmit and go back to receive.

◦ Repeat the above steps for all bands.

◦ Now, review again the values stored for the “5W PWR Adjust”

settings for each band.

▪ None of the band-gain values should be higher “75%” values

that you calculated for the “Full PWR Adjust” settings for the

corresponding bands.

▪ If you set any “5W PWR Adjust” parameters higher than

then corresponding “Full PWR Adjust for the same band,

reduce the “5W PWR Adjust” to be no higher.

◦ Once you have determined the proper values, press-and-hold the

F1 button to save them to EEPROM.

• Wattmeter/SWR meter adjustment:

◦ Connect a dummy load to the transmitter

◦ Make certain that the MICROPHONE input is selected and turn

the microphone gain setting to minimum.

◦ Set to USB or LSB.

◦ Set the band to 10 meters.

◦ Set the power to 0.5 watts.

◦ Go to the CALIBRATION menu and set the item “Disp. Pwr

(mw)” to ON. This will enable the display of the detected power in

milliwatts in a portion of the screen just below the “RIT” indicator

with first number indicating forward power and the second

indicating reverse power.

◦ With NO audio present (e.g. a quiet room or keying the

transceiver with no microphone present) observe numbers in the

upper-left corner of the screen, just below the “RIT” indicator, and

adjust the calibration menu setting “Pwr. Det. Null” to zero these

numbers.

◦ Once the NULL value has been determined, un-key the

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transmitter and then press-and-hold the F1 button to save the setting

to memory.

◦ It is possible that these two numbers will not exactly coincide at

zero, but they should be within less than 5 units of each other. These

numbers will also vary slightly in a random fashion: It is better that

these numbers occasionally go slightly above zero than always stay

below zero.

◦ If the forward and reverse power are more different than 5 or so

points, check the following:

▪ Make sure that there is no audio present – not even noise!

There must be NO transmit power in this step. If necessary, set

“10m 5 W PWR Adjust” setting for the current band to the

lowest possible number, noting the original setting: You will

have to momentarily set the power to 5 watts to allow this

adjustment – but remember to set it back to 0.5 watts. Once you

are done, restore the original “10m 5 W PWR Adjust” value

and then press-and-hold F1 when done to save the setting.

▪ If the forward/reverse readings are still different, make certain

that you have installed the proper-value components during the

modification.

• If resistors of lower precision than 1% were used (e.g. 5%)

it is possible that normal tolerance variations are responsible

for these differences, in which case it may be necessary to

use a digital ohmmeter to match several pairs of resistors to

within a fraction of a percent.

• Check to see if your solder is based on “Water soluble”

flux: If it is, be absolutely certain that this flux is removed as

it can become conductive upon absorbing moisture from the

air. This type of flux is more common with “Lead Free”

solders.

▪ If you still get radically different forward/reverse readings, check

the voltages on pins 9 and 10 of the 30 pin connector: They should

be equal, within a few millivolts. If not, check wiring.

◦ After functioning of the VSWR meter is verified and the OTHER

VSWR/Power meter (e.g.T2/T3) related modifications discussed in this

document have been performed, the wattmeter may be calibrated as

follows.

▪ DO NOT PERFORM THESE STEPS UNLESS YOU HAVE

PROPERLY HEATSINKED THE FINAL TRANSISTORS!:

▪ Connect a known-good 50 ohm dummy load and wattmeter to the

output of the HS1.

▪ Set the transmit power to 5 watts.

▪ Set the mode to USB, LSB or CW.

▪ Go to the “Pwr. Det. Null” item and set it to ON. This will cause

the forward and reverse power to be displayed just below the RIT

indicator, in milliwatts.

▪ Go to the “80m Coupling Adj.” item in the configuration menu.

▪ Press the TUNE to activate the transmitter.

▪ Quickly adjust the “80m Coupling Adj.” parameter so that the

displayed forward power in milliwatts matches your wattmeter's

power reading. (Remember: 5000 milliwatts = 5

watts.)

▪ Repeat the above steps for 40 meters using the “40m Coupling

Adj.” parameter.

▪ Repeat the above steps for 20 meters using the the “20m

Coupling Adj.” parameter.

▪ Repeat the above steps using the “15m Coupling Adj.”, using a

frequency on 12 meters.

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▪ Once you are done setting these values, press-and-hold the F1

button to save the settings to EEPROM.

• Frequency Calibration: This step requires several things:

▪ A known-accurate frequency source. This could be a

precision oscillator/test equipment or an off-air signal from a

time station such as WWV.

▪ A means of accurately determining an audio frequency. This

could be a frequency counter or a computer with sound card

with a known-accurate sample rate running an audio analysis

program.

◦ Set the receiver to USB mode.

◦ If the signal source is available on multiple frequencies, pick the

highest frequency available.

◦ Tune the receiver 1 kHz below the frequency of the selected

reference frequency.

◦ Set the tuning step size to 1 Hz.

◦ Couple the output of the receiver to the audio frequency

measuring device so that you get a reading.

◦ Go to the calibration menu item “Freq. Calibrate” and adjust it

to obtain a precise 1 kHz audio frequency.

▪ Note: It is possible that the Si570 may be off frequency by

hundreds of Hz – or even several kHz. You may change the

frequency step size to facilitate this adjustment.

• TX and RX I/Q Phase/Balance adjustments:

◦ The procedures for adjusting TX and RX I/Q Phase and balance

are detailed in later sections of this manual and should be reviewed.

Additional settings:

The following settings should be known to the HS1 operator. Please refer to

the previous sections containing the menu items for more details on their

use.

• Voltmeter Cal. - This calibrates the on-screen voltmeter: Only a

known-accurate voltmeter should be used as a reference. Note that the

voltmeter display updates only once every second or so.

• Max Volume – This puts a limit in the maximum volume setting –

particularly useful if one primarily uses headphones where loud sounds may

cause hearing damage.

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Recommended procedure for adjusting RX IQ gain and phase

adjustments –

Frequency translate mode ENABLED:

1. Set the HS1 to LSB mode.

2. Set the AGC to FAST mode so that the receiver recovers more

quickly from the "clicks" that occur during the phase adjustments.

3. Tune in a strong, constant signal. This could be a shortwave broadcast

station or a signal generator – a signal generator is preferred.

4. Tune the HS1 dial frequency 1 kHz above the carrier frequency to

obtain a strong 1kHz audio note. Example: If your signal generator is

set to 7200 kHz, you would tune to 7201 kHz.

5. Now tune the dial 2 kHz lower, that is to a frequency 1 kHz below

that of the signal generator: You may hear a 1 kHz tone “leaking”

through from the other side. Following the example, the dial frequency

would now read 7199 kHz.

6. If you hear a tone, adjust “LSB RX IQ Bal.” to minimize the amount

of leakage. Now adjust “LSB RX IQ Phase” to further minimize the

signal leakage. If no obvious improvement is obtained, set this to the

default value (0). In any case, note the two values obtained.

7. If you have selected the “RX LO LOW” mode of frequency

translation, tune the dial 11 kHz higher than the generator's frequency.

Following the example, the dial frequency should now be 7211 kHz. If

the “RX LO HIGH” mode of frequency translation is selected, tune the

dial 13 kHz lower than the generator's frequency. Following the

example, the dial frequency would now be 7187 kHz.

8. If you hear the "leakage", adjust “LSB RX IQ Bal.” and “LSB RX

IQ Phase” alternatively to minimize it. Once minimized, note the two

values obtained.

9. Use the set of values obtained during the adjustment that caused the

most difference when adjusting both the “LSB RX IQ Bal.” and

“LSB RX IQ Phase” settings, with preference on the values obtained

in step 7.

10. Repeat the steps, above, in USB mode, adjusting the parameter

“USB RX IQ Bal.” and “USB RX IQ Phase”.

◦ For this procedure the frequency used in Step 5 would modified

such that one would tune 2 kHz above the frequency where a 1

kHz tone would be heard, or 1 kHz above the signal generator

frequency. (The dial frequency would be 7201 kHz, using the

example above.)

◦ If “RX LO LOW” translate mode is used, the frequency used in

Step 7 would be 13 kHz above that of the frequency generator.

(7213 kHz, using the example above.)

◦ If “RX LO HIGH” translate mode is used, the frequency used in

Step 7 would be 11 kHz below that of the frequency generator.

(7189 kHz, using the example above.)

11. Repeat the steps, above, in AM and FM modes, adjusting the

parameters “AM RX IQ Bal.” and “FM RX IQ Bal.”, respectively.

Once you have completed the procedure, remember to set the AGC

mode back to what it had been previously and to save the new settings

by pressing-and-holding the POWER button to turn off the transceiver.

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Recommended procedure for adjusting RX IQ gain and phase

adjustments –

Frequency translate mode DISABLED:

Do not perform the following procedure unless you operate the HS1

transceiver with “Frequency Translate” set to “disabled” for a specific

technical reason. Because using “Frequency Translate” improves most

aspects of operation of the transceiver it is expected that it will normally be

used.

This procedure is included for completeness.

1) Set the HS1 to LSB mode

2) Set the AGC to FAST mode so that the receiver recovers more

quickly from the "clicks" that occur during the phase adjustments.

3) Tune in a strong, constant signal. This could be a shortwave

broadcast station or a signal generator – a signal generator is preferred.

4) Tune the HS1 dial frequency 1 kHz above the carrier frequency to

obtain a strong 1 kHz audio note.

5) Now tune the HS1 dial frequency 2 kHz lower (e.g. 1kHz below)

the carrier frequency. You should be able to hear the same 1 kHz audio

note, but much more weakly.

6) If you can NOT hear this note, re-check the frequency. If the

frequency is correct and you cannot hear the "leakage", either the test

signal is not strong/clear enough or your opposite sideband attenuation

is sufficient and you should proceed to adjusting the USB gain/phase

adjustments.

7) If you hear the "leakage", adjust the LSB RX IQ Bal. to minimize

it.

8) Once minimized using the RX IQ Bal., adjust the RX IQ Phase to

further minimize the "leakage". Note that adjusting the phase will

cause "clicking" which may upset the AGC/Smeter briefly.

9) Once the LSB leakage has been minimized, repeat the above

procedure in USB mode, but tuning below in step 4 and above in step

5.

Once you have completed the procedure, remember to set the AGC

mode back to what it had been previously and to save the new settings

by pressing-and-holding the POWER button to turn off the transceiver.

NOTE for CW operators who use "lower" CW sidetone frequencies:

If you use the HS1 primarily for CW, use rather low frequency CW notes

and sidetone frequencies (400-550 Hz) and notice "leakage" from the

opposite sideband after following the above procedure, you may choose to

perform the above procedure at the approximate frequency CW sidetone

frequency rather than 1000 Hz. This is because of the way the Hibert

Transformer works and the fact that lower frequencies (<500 Hz) can have

poorer opposite-sideband rejection.

If you choose a different, lower sidetone frequency note that you may

sacrifice opposite sideband rejection at higher frequencies, particularly if

you null it at too-low a frequency! You should carefully choose your

"alternate" frequency as to provide a good compromise good opposite

sideband rejection at the desired frequency and higher frequencies (e.g. 750

Hz and up).

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Recommended procedure for adjusting TX IQ gain and phase

adjustments

Frequency translate mode ENABLED:

1. Loosely couple your transmitter to a receiver that is connected to a

computer running a program with a waterfall display. Do NOT connect

the HS1 transmitter to your receiver, but connect it to a dummy load

and place an antenna coupling from your computer-connected receiver

nearish the HS1's RF output so that it gets adequate signal. A program

such as Spectran is recommended. (The Spectrum Lab program will

also work, but is more complicated to use.)

2. Switch to LSB mode on the HS1.

3. Set the HS1 to 1 Watt mode.

4. Switch to USB mode on the computer-connected receiver. (Yes,

USB.)

5. Tune both the HS1 and the computer-connected receiver to the same

frequency.

6. Press the TUNE button. The audio on the HS1 audio should mute and

you should see, on the waterfall display, a signal 750 Hz below the HS1

dial display frequency. If the dial frequency is 7200 kHz, the main LSB

signal will be on 7199.25 kHz, 750 Hz below 7200 kHz.

7. Now look at the opposite sideband signal (the USB image) at

7200.75 kHz and adjust “LSB TX IQ Phase” to minimize it. There will

likely not be much difference in this signal, perhaps 2-10 dB. If there is

no easily discernible difference using your measuring method set this

value to zero.

8. Now, adjust “LSB TX IQ Bal” for maximum suppression at the

frequency of the translated image. This signal will be located

approximately 12 kHz away from the dial frequency. You should

Enable/Disable TUNE mode and/or adjust the setting of “LSB TX IQ

Bal” to positively identify this image signal.

Note that this adjustment may not null it completely out, but there

should be an obvious minimum setting.

◦ If the frequency translate mode is set to “RX LO Low” find a

signal 11.25 kHz below the dial frequency. In the example where

the dial frequency is 7200 kHz, this signal would be found at

7188.75 kHz.

9. Press TUNE again to exit transmit mode and switch to USB mode,

the computer-connected receiver to LSB, and press TUNE to produce

a transmit test signal.

10. Press the TUNE button. The audio on the HS1 audio should mute

and you should see, on the waterfall display, a signal 750 Hz above the

HS1 dial display frequency. If the dial frequency is 7200 kHz, the main

USB signal will be on 7200.75 kHz, 750 Hz below 7200 kHz.

11. Now look at the opposite sideband signal (the LSB image) at

7.19925 MHz and adjust “USB TX IQ Phase” to minimize it. There

will likely not be much difference in this signal, perhaps 2-10 dB. If

there is no easily discernible difference using your measuring method

set this value to zero.

12. Now, adjust “USB TX IQ Bal” for maximum suppression at the

frequency of the translated image. This signal will be located

approximately 12 kHz away from the dial frequency. You should

Enable/Disable TUNE mode and/or adjust the setting of “USB TX IQ

Bal” to positively identify this image signal. Note that this adjustment

may not null it completely out, but there should be an obvious

minimum setting.

◦ If the frequency translate mode is set to “RX LO Low” find a

signal 12.75 kHz below the dial frequency. In the example where

the dial frequency is 7200 kHz, this signal would be found at

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7187.25 kHz.

◦ If the frequency translate mode is set to “RX LO High” find a

signal 11.250 kHz above the dial frequency. In the example where

the dial frequency is 7200 kHz, this signal would be found at

7211.25 kHz.

13. Press TUNE again to return to receive mode.

14. Repeat the above steps for both AM and FM mode using the

parameters “AM TX IQ Bal.” and “FM TX IQ Bal.”, respectively.

◦ NOTE: In both AM and FM mode the TUNE function will not

work: Simply key the transmitter and use the constant carrier

produced by those modes as your test signal.

Important:

• When you are done write down the phase and gain settings, then power off

using the POWER button to save the settings. Power up again and return to

the menu to verify that they were saved.

Recommended procedure for adjusting TX IQ gain and phase

adjustments

Frequency translate mode DISABLED:

Do not perform the following procedure unless you operate the HS1

transceiver with “Frequency Translate” set to “disabled” for a specific

technical reason. Because using “Frequency Translate” improves most

aspects of operation of the transceiver it is expected that it will normally

be used.

This procedure is included for completeness.

1. Loosely couple your transmitter to a receiver that is connected to a

computer running a program with a waterfall display. Do NOT connect

the HS1 transmitter to your receiver, but connect it to a dummy load

and place an antenna coupling from your computer-connected receiver

nearish the HS1's RF output so that it gets adequate signal. A program

such as Spectran is recommended. (The Spectrum Lab program will

also work, but is more complicated to use.)

2. Switch to LSB mode on the HS1.

3. Set the HS1 to 1 Watt mode.

4. Switch to USB mode on the computer-connected receiver. (Yes,

USB.)

5. Tune both the HS1 and the computer-connected receiver to the same

frequency.

6. Press TUNE mode. You will hear a 750 Hz tone from the HS1 and

see it on the waterfall display, see a signal 750 Hz below the HS1 dial

display frequency. Note: You'll have to do some simple math to figure

out where these frequency components will land on the waterfall!

7. If you adjust the LSB TX IQ Bal. you should see the signal 750 Hz

above the HS1 dial display frequency go up and down. Null this upper

frequency as much as possible.

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8. Note: Unless the IQ Gain balance is nulled as much as possible,

nulling of the Phase adjustment will not be possible.

9. Once the best nulling is obtained with the LSB TX IQ Bal., adjust

the LSB TX IQ Phase. It will "click" on each adjustment, so wait for

the waterfall screen to clear after each adjustment.

10. Once the best phase null is obtained, go back and forth between the

gain and phase for the best null.

11. Press TUNE again to exit TUNE mode.

12. Switch the HS1 to USB mode and the computer-connected receiver

to LSB mode.

13. Switch the computer-connected receiver in LSB mode, but this

time null out the 750 Hz tone BELOW the HS1 dial frequency, having

done the math to figure out where the frequency components will land!

When you are done write down the phase and gain settings, then power off

using the POWER button to save the settings. Power up again and return to

the menu to verify that they were saved.

Calibrating the HS1's operating frequency

The HS1 transceiver has provisions for calibrating the display frequency to

that of known-accurate frequency references such as a time station or a

frequency reference using the “Freq. Calibrate” menu item.

This menu item is adjustable from -9999 to 9999, this representing Hz at a

frequency of 14.000 MHz, proportionally affecting all operating

frequencies. When making this adjustment, use the STEP- and STEP+

buttons to select the step size: Note that only the 1 Hz, 10 Hz, 100 Hz, and 1

kHz sizes are actually useful considering the +/-9999Hz adjustment range!

To calibrate the HS1 frequency:

If you use the TCXO feature of the HS1:

• IMPORTANT: First, make sure that you have thermally bonded the

Si570 (U8) and the temperature sensor chip, U10 with a piece of

copper or aluminum that is at least 1mm thick. It is recommended that

metal-filled (e.g. grey or black) epoxy be used for this, although clear

epoxy will also work.

It should be noted the RTV (e.g. “Silicone”) adhesive does not conduct

heat very well and that cyanoacrylate (e.g. “Super”) glue works quite

poorly as it will likely leave a gap.

• Set RIT to zero by adjusting ENC3 so the small frequency display's

frequency matches that of the main (RX) frequency display. (The RIT

always defaults to “zero” on power-up.)

• If you have a known-accurate frequency counter, couple it to with a

capacitor or highimpedance probe to pin 2 or 14 of U15 on the RF

board: You should see the receive frequency: Adjust the “Freq.

Calibrate” parameter so that the frequency on the counter and the

HS1 display agree.

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• If a sensitive receiver or service monitor is available, it may be

possible to detect the local oscillator radiating from the HS1 and

observe the oscillator frequency directly. If you do this, temporarily set

the “RX/TX Freq Xlate” setting to OFF so that the local oscillator

frequency is the same as the displayed frequency. If you don't set it to

“off” note that the local oscillator will be exactly 6 kHz above or below

the displayed frequency in receive, depending on the setting of this

parameter.

• If adjusting it using the "zero-beat" method on receive, set the

bandwidth to 3.6 kHz or to a “wide” filter and tune in a

known-accurate signal such as WWV. When setting the frequency,

switch between USB and LSB to verify that there is no difference in

the way it sounds. The use of one of the wider filters (>=3.6 kHz) and

the extended low frequency response makes zerobeat adjustments

easier, particularly if headphones are used.

• If you have a known signal source and a way to accurately measure

audio frequency, tune in that signal source, offset by a given amount

(say, 1 kHz) and then adjust the HS1 for a precise 1 kHz audio tone. A

computer running a sound card audio analysis program such as

Spectran or Spectrum Lab – or even a PSK31 program – can yield

accurate frequency information, but be aware that many computers

(particularly laptops or so-called “netbooks”) can have inaccurate

sample rates that cause erroneous frequency measurements.

Before you trust the computer to give an accurate frequency reading, it

is recommend that you feed audio from a known-accurate source and

check calibration. One source of such a signal is the audio from WWV

or WWVH (tuned using AM – never SSB!) that transmit tones of 500 or

600 Hz on alternate minutes, depending on the exact time and to which

station you are listening.

If, for some reason, the above steps do not work or you you do not wish to

perform them at this time, you may do the following:

• The calibration procedure is the same as above, but note that there will be a

slight frequency shift when you switch between the TCXO ON and OFF (or

to the “Stopped”) mode so be sure to perform the frequency calibration in

whatever mode you intend to use.

• You should expect an observable and possibly significant frequency shift as

the temperature changes!

If you do NOT use the TCXO feature of the HS1:

For most users there is no reason NOT to use the TCXO feature of the HS1

as it will greatly improve frequency stability with changing temperature.

The main reasons why one might not want to use it include:

• For testing/debugging. Perhaps, while building, the function does not

work or the temperature sensor is not available.

• To characterize the temperature drift. If you wanted to modify the

source code to model the Si570 in your transceiver to minimize drift you

would turn it off and measure the frequency change at 14.000 MHz and

apply these corrections.

• You are hearing a “tick-tick” sound in your audio – particularly on

higher bands, caused by the data polling of the temperature data.

If you are having trouble with the “tick-tick” it may be that you are using a

UI board that is older than revision 0.4 that has not been modified and/or

you have not turned on the “RX/TX Freq Xlate” mode (preferably to “RX

LO LOW”)

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Explanation of the “Frequency Translation” feature

PLEASE read the following VERY carefully!

Menu item “RX/TX Freq Xlate” selects the enabling/disabling of baseband

frequency translation in the receiver/transmitter. When the translation is

active, instead of the receiver operating at and around "DC", the signals are

mathematically shifted from 6 kHz (above or below – user-selectable).

Whether or not frequency translate mode is enabled is displayed on the

start-up splash screen.

Performing this frequency shift can help forgive a lot of the "sins" that

occur with "DC" conversions - the most obvious of which are that ANY

noises in the power supply as well as the 1/F noises of op amps, mixers,

A/D converters and the like tend to show right up in the received audio.

With the signals at microvolt levels, it is a real fight to minimize these

signals! These signals/problems can show up as:

• Hum

• Howling

• Audio feedback, particularly at higher volumes

• Buzzing with the dimming of the backlight

• Noises from the I2C communications (e.g. “ticking”)

It should be noted that these code modifications DO NOT relieve the builder

of the strong recommendation that one perform the modifications in the

"HS1 Board Modifications" file, particularly the U3a and MCU and LCD

power supply modifications (for UI board 0.3) but they should go a long

way toward reducing the artifacts that can still occur even after making

those modifications - even to the point of gaining an extra S-unit or two in

sensitivity.

Menu item “RX/TX Freq Xlate” has the following options:

• OFF - This is the original operation of the transceiver with the

receive (and transmit) signals operating at and around zero Hz.

• RX LO HIGH - In this mode the signals are shifted BELOW zero

Hz by 6 kHz, requiring that the local oscillator be shifted up by the

same amount. The received signals are tuned at the first graticule left

of center on the spectrum scope and waterfall display when “magnify”

mode is turned off.

• RX LO LOW - In this mode the signals are shifted ABOVE zero Hz

by 6 kHz, requiring that the local oscillator be shifted down by the

same amount. The received signals are tuned at the first graticule right

of center on the spectrum scope and waterfall display when “magnify”

mode is turned off.

Additional options may be added in the future.

The use of RX LO HIGH or RX LO LOW is entirely up to the operator's

preference, but it may be observed that additional rejection of some of the

noises (e.g. the “tick” from the I2C communications of the temperature

sensor) may be reduced when one setting is selected over the other.

Frequency translation mode is necessary for AM TX and for FM

RX/TX operation.

For various reasons (e.g. the use of USB on higher bands where the

potential for zero-HZ interference is highest) the use of “RX LO LOW”

is recommended for best performance!

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64

Quirks and side-effects of the frequency translation mode:

Spectrum Scope/Waterfall Display offset:

If the menu item “Spec/Waterfall 2x magnify” is set to Off when the

translate mode is activated, you will note that the receive signal is no longer

in the center of the spectrum scope or waterfall display!

Along the bottom of the spectrum scope you'll observe that the frequency

display is changed, with the frequency in kHz being displayed in full under

the graticule, being shifted left or right as noted above.

If you have used other SDR software – particularly “sound card” SDR

rigs on computers – you will already be familiar with this sort of shift!

If “Magnify” mode is activated, the receive frequency is always displayed in

the center of the screen.

Translation in transmit mode:

This frequency translation is used on SSB transmit as well, slightly

improving the SSB audio quality when this mode is activated and it also

makes it possible to implement the transmission of AM signals using this

type of hardware.

Because of this frequency translation, in SSB transmit, you will also note

that if you monitor the LINE OUT jack, you will no longer hear the SSB

transmit audio directly. The reason for this is that there is only ONE D/A

converter on the HS1 and with the frequency translation occurring, it is

possible only to patch through the signal being fed to the modulator - which

is no longer at "baseband." In theory, it should be possible to make a

modification to the radio to use one of the existing 8-bit D/A channels to

provide a "local" audio monitoring source, but this is something to be

explored.

In CW mode things are a bit more complicated as there is the need for a

sidetone - and the only way to generate a sidetone is via the monitoring of

the audio being sent to the modulators. For this reason, frequency translation

cannot be done in CW mode so the local oscillator must be shifted between

receive and transmit - and THIS is where the bugs may show up again.

Effects in AM mode:

The use of frequency translation removes the problem of the “Hole” when

using “AM” mode, eliminating the need to off-tune the signal to prevent its

carrier from being at “zero IF”, in the middle. As noted above it has also

allowed the implementation of full-carrier, double-sideband AM: It is also

possible to implement single-sideband, full-carrier AM, but this feature is not

implemented at this time.

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65

Button(s)

Brief press

Press-and-hold >1 second

Power

Change display brightness

Power on and power off/save settings to memory

M1

Select AFG and CMP or STG

M2

Select RFG and DSP or NB

Switch between DSP and NB

M3

Select RIT and MIC or LIN

Switch between MIC or LIN

G1

Change operational mode

Change operational mode - including disabled mode(s)

G2

Change DSP mode

Enable/Disable DSP without changing mode

G3

Change transmit power level

Generate CW Sidetone reference (CW/LSB/USB modes only)

G4

Change receive bandwidth (except in FM mode)

Change receive bandwidth – including disabled bandwidth(s)

Generate tone burst (FM TX only)

BAND-

Change to different band

BAND+

Change to different band

STEP-

Change step size

Temporarily change to smaller tuning step size

STEP+

Change step size

Temporarily change to larger tuning step size

STEP- & STEP+

Lock/Unlock tuning knob

POWER & BAND-

Toggle display backlight auto-off

BAND- & BAND+

Toggle Spectrum Scope and Waterfall modes

HS1 Key function matrix

Main operational (receive/transmit) mode:

Menu mode:

F1

Exit MENU mode

Save settings to memory

F2

Set selected menu item to default

F3

Move to previous menu screen

Move to beginning of current

menu

F4

Move to next menu screen

Move to end of current menu

F5

Toggle TUNE mode

Enable/Disable transmit toggle

• Pressing-and-holding F1, F3 and F5 simultaneously while powering up the radio will cause defaults to be loaded. The user must either disconnect power to retain the old settings or

press-and-hold the POWER button to overwrite them with defaults. All configurations, adjustments, frequencies and mode settings will be lost!

• Pressing-and-holding a button (other than POWER) while powering up the radio will cause it to enter a “button test” mode. If multiple keys are pressed, only the name of the button with the

highest precedence will be displayed. In decreasing order, the precedence is: M2, G3, G2, BNDM, G4, M3, STEPM, STEPP, M1, M3, F1, F2, F4, BNDP, F5, G1 and POWER

• The “Band-” and “Band+” and the “Step-” and “Step+” functions may be swapped using menu selections.

F1

Enter MENU mode

Save settings to memory

F2

Change meter mode

F3

Toggle SPLIT mode on/off

F4

Toggle VFO A/B

Copy active VFO to inactive

VFO (A=B or B=A)

F5

Toggle TUNE mode

Enable/Disable transmit toggle

Ailunce HS1 User ’s Manual

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group. Please make sure that the “Frequency Translate” function is

active as this will also reduce this noise.

• There may be a lingering bug in the CW mode in which the transceiver

momentarily “hangs” on rare occasions, particularly when going quickly

from TX, to RX and then back to TX again. It is believed that this bug has

been fixed, but if it does occur, increase the length of the “CW TX- >RX

Delay” parameter slightly and please report its occurrence and the relating

circumstances on the Yahoo group.

• If the various modifications to improve receiver performance have been

performed (e.g. the “U3a” mod, a separate regulator for the MCU, the 4.7

ohm resistor in the 8 volt supply for the audio amplifier, the resistor/filter for

the LCD supply, etc.) the receiver sensitivity will increase to the point that

EMI from the LCD's data bus can get into the receiver. When the spectrum

scope display is updated, this can cause a “Helicopter”-like sound which

may be significantly reduced by placing a metal shield between the UI and

RF boards. This shield may be any type of metal, but it must be insulated on

both sides to prevent its shorting components. This shield need not be

grounded to effect significant improvement in receiver performance. This

effect is less apparent with the LCD operating in SPI mode. The board

modifications were incorporated into UI board versions >=0.4, but it is

recommended that a metal shield be placed between the two boards no

matter which version of boards you use.

• Starting with version 0.0.211, the “build” number (“211” for example) is

stored in the EEPROM and compared upon boot-up. If this is different, it is

assumed that a new version of firmware has been loaded and new EEPROM

variables are automatically initialized. Note that this is triggered ONLY if

the build number of the loaded firmware is different from what was

previously loaded into the radio.

Operational notes, quirks, and known bugs:

• CW operation will be impaired while in the menu system! It is

recommended that one NOT transmit in CW while the menu system is being

displayed as the dit-dah timing will be disrupted!

• In the sudden presence of a strong, steady signal, a “Tick-tick” sound may

be heard for a few seconds, accompanied by the lower portion (“S0-S9”) of

the S-Meter turning red. This sound is the result of the automatic gain

adjustment of the A/D converter in the codec being quickly adjusted to

prevent overload, with the “tick” sounds being due to the large step sizes of

the gain reduction. In normal operation, in the presence of modulation (e.g.

audio) rather than a steady carrier this artifact is inaudible. For more

information see the menu item “RX Codec Gain”.

• When the transceiver is powered up one of the pieces of information that is

displayed is the interface mode of the LCD. The desired mode is “Parallel”,

which is obtained with UI board revisions 0.3 and later with

appropriately-jumpered HY-28B LCD displays. If you have have a version

0.3 board and this newer display, but the startup message indicates that the

LCD interface mode is SPI, you may consider CAREFULLY removing the

LCD and properly setting its jumpers to achieve parallel mode.

• If you have an older LCD and/or board that runs in SPI mode you may

wish to change the parameter “Spec. Scope Filter” to 1 or 2 to reduce its

strength and speed the response to changing signals.

• If you experience a one-second “Tick” sound on higher bands (15, 12, 10

meters) you may wish to perform the modification that suppresses this

problems. Prior to making these modifications, this “tick” sound may be

suppressed by setting the menu parameter “TCXO Off/On/Stop” to “Stop”.

Note that this will halt polling of the temperature sensor, disabling the

temperature display and the ability of the temperature drift of the synthesizer

to be compensated for temperature change.

These modifications may be found in the “KA7OEI” folder on the Yahoo

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• Please refer to the “board modification” document for information on

reducing the amount of induced noise caused by the LCD when the display

is dimmed. This document may be found in the FILES section of the

YAHOO group in the KA7OEI folder. Changes have been incorporated in

version 0.4 of the UI board to reduce this along with using the “Frequency

Translate” function.

• When the LCD display is dimmed, it is a known that the display will flash

somewhat when operating CW. It is hoped that this will be resolved in a

later version of firmware.

• Starting with version 0.0.219.x the usage of “major” and “minor” version

numbering has changed. Prior to this the “major” version numbering was not

used (e.g. 0.0.0.211, 0.0.0.112). Now, both major and minor version

numbering is used, as in “0.0.219.15”, “0.0.219.16”, etc.

The HS1 transceiver consists of two boards: The UI (User Interface) board

that contains the MCU (computer) and display, along with the audio

input/output and buttons and the RF (Radio Frequency) board that contains

the power supply, frequency synthesizer, transmit and receive mixers,

transmit power amplifiers and bandpass and lowpass filters. These two

boards are connected together via a 30 pin SIP (Single Inline Pin) connector

to form one compact unit.

RF Board:

Power Supply:

Located on the RF board, DC power, ranging from 9 to 16 volts, is input via

J1, passing through fuse F1 which could be a one-time fuse or a

self-resetting “PTC” type fuse, depending on the builder's choice. Following

this is D1 that, in the event of inadvertent application of reverse polarity, will

conduct and cause the fuse to blow, protecting the radio from permanent

damage.

Providing a low impedance DC source for transceiver, C27 filters the input

voltage upon application to the “unswitched” DC circuits (VCC_12V) and

switchable regulator U3 while R13 and R14 scale the input voltage to a

range suitable for measurement by the MCU with C31 providing the

necessary lowimpedance AC input for its A/D input.

R9 and R10 form a voltage divider connected to the ON/OFF pin (pin 2) of

voltage regulator U3 that, when pulled to ground, enables its output, turning

on its output which is “programmed” for a nominal 8 volts via resistors R11

Circuit description of the HS1:

Ailunce HS1 User ’s Manual

68

and R12. Pin 2 may be pulled down via diode pack D2 by either a press of

the POWER button on the UI board or by an output of the MCU itself: In

normal operation, the MCU keeps this pin (“PowerDown”) low to keep the

transceiver powered up, but releases it (e.g. allows it to go high) when a

power down is permitted: This is why, when powering off the transceiver, it

does not actually turn off until one releases the POWER button.

The output of U3, “VCC_8V” is provided to a number of places: To the

LM386 audio amplifier on the UI board and to U4, a 5 volt regulator on the

RF board. The output of the 5 volt regulator, “VCC_5V”, is then, in turn,

distributed to the majority of the circuits on the RF board as well as the main

power for the LCD on the UI board in addition. The 5 volt supply is also

used to power U5, a low-dropout 3.3 volt regulator on the RF board which is

used to power the RF synthesizer and related circuitry and some of the audio

circuitry on the UI board as well as a separate 3.3 volt low-dropout regulator

present on the UI board used to power the MCU.

An Si570 clock generator (U8) is used as the RF signal source for the HS1

transceiver. This device, capable of part-per-billion tuning resolution,

operates at four times the TX/RX frequency and is capable of tuning from at

least 10 MHz (2.5 MHz) through 120 MHz (30 MHz) – although individual

devices can typically tune beyond this range allowing, at least partial or

complete coverage of the 160 meter amateur band. The Si570 is tuned via an

SPI (serial) interface, controlled by the MCU and its RF output is first

buffered by U9 to “square” it as the Si570's output could be a lower-level

sine. The output of this is then fed to U11 which generates a quadrature

signal at the TX/RX frequency. These signals are then fed to U12 and U13

which provide separate differential drive signals at 5 volt logic levels for the

receive and transmit mixers.

U10 is an SPI-interface temperature sensor that is thermally bonded to U8,

typically by using epoxy to adhere a piece of aluminum or copper to bridge

the top of the two parts so that they track each other. The Si570, being

originally intended for a generalized clock source in networking applications

does not have a particularly stable internal crystal reference and as such, its

absolute frequency can vary significantly with temperature. Because the

nature of this variance is repeatable and dependent on temperature, the

resulting frequency drift may be compensated by monitoring the Si570's

temperature and applying corrections in software.

Antenna Switching and Lowpass Fltering:

The RF signals are applied via J1, a BNC connector. DS1, a standard neon

discharge tube, with its 60-90 volt “breakover” voltage, offers a degree of

protection to the transceiver against brief transients such as those related to

lightning discharges while the DC continuity of T2/T3 prevent the

accumulation of static charge.

Transformers T2 and T3 form what is known as a “Tandem Coupler”, being

directionally sensitive to the flow of RF current through the primary of T2.

For example, if the load connected to J1 is matched to 50 ohms, a sample of

that RF output will appear at the junction of R57 and D5 but none will

appear at the junction of R61 and D6. If there is a mismatched load a J1, the

amount of reflected power will be proportionally indicated by the amount of

RF appearing at the junctions of R57/D5 and R61/D6 with the latter

indicating the amount of reflected RF.

The signal feeding the Tandem Coupler “ANT_MET” comes from the

lowpass filter selection which is accomplished through the use of

magnetically latching relays. These have the advantage of needing to be

RF Synthesizer:

Ailunce HS1 User ’s Manual

69

energized only briefly, holding their state indefinitely until change and thus

saving power. By setting the appropriate combination of relays and contacts

the appropriate low-pass filter may placed inline. The relays themselves are

driven by U14 which decodes a brief pulse from the MCU to place them in

the desired configuration upon power-up and/or when the frequency/bands

are changed.

The “input” side of the low-pass filtering is the “TX_PA_OUT” line which

connects to two places:

The “top” of T7, the output matching filter for the power amplifier and the

PIN diode T/R switch. When in receive mode PIN diode D4 is turned off

and PIN diode D3 is turned on by setting lines “ANT_TX_ON” low and

“ANT_RX_ON” high, respectively, providing a signal path from

“TX_PA_OUT” to “RX_ANT” and to the receive section.

When in transmit mode, the “ANT_TX_ON” line goes high and

“ANT_RX_ON” line goes low, causing diode D4 to turn on which shorts the

signals at that point to ground and putting a reverse bias across D3,

increasing its “off” isolation even more, further improving the isolation of

the receiver input circuitry from the transmitter output.

It is worth noting that the PIN diodes in this circuit do not carry RF power

as they are not in the transmit path, but must be rated to stand off the peak

RF voltage that could occur at full RF output in a severe mismatch

condition: The 200 volt rating of the specified diodes offers comfortable

margin.

It is worth noting that in receive mode, the signal path is connected in

parallel with RF output transformer, T7 and thus the RF finals themselves.

While this can cause a small amount of signal reduction owing to the losses

of T7 and the shunting effects of the RF power transistors Q5 and Q6, this

effect is rather minimal. This approach – quite common in QRP rigs – was

taken to simplify the circuity and eliminate the need to insert another

low-loss switch, either a relay or high-power PIN diode, in the transmit

signal path.

Bandpass Filters:

The bandpass filter network is used for both receive and transmit, the roles

being selected by the configuration of switches U1 and U2 which both select

which filter is used and which is connected to what input/output.

In receive mode the “RX_ANT” line from the PIN diode switch is routed to

the appropriate filter, selected by control signals from the MCU via U1.

Passing through the appropriate filter, the signal then passes through U2

which uses the same signals as U1 which then applies the now-filtered signal

to the “RX_QSD_IN” line.

In transmit mode the PTT line switches U1 and U2 to the “other” set of

switches, routing the signal from transmit mixer “TX_MIX”, through the

filter, to the PA driver stage via “TX_PA_IN”.

Shown as “optional”, there is a resistor network that may be populated to

provide a bias voltage for switches U1 and U2 in the bandpass filter

network. At high signal levels biasing these switches somewhere around

“mid supply” may improve linearity (reduce distortion) but this may not be

noted under normal operation. If in doubt, these components may be

installed with absolutely no deleterious side effects.

Ailunce HS1 User ’s Manual

70

RX Detector:

The “RX_QSD_IN” signal from the bandpass filter is applied to RF

preamplifier Q1 which has approximately 22 dB gain. This signal is then

passed through T1 which produces a differential signal that is applied to a

Quadrature Sampling Detector (a.k.a. “Tayloe” Detector).

This mixer works by turning on a switch at the desired receive frequency

(e.g. the local oscillator frequency) for a portion of the RF cycle – and then

turning it off again. If there was signal on the input of the detector was

“close” to that of the local oscillator signal, some of its energy will be stored

in the capacitor connected to its output and if the voltage on that capacitor is

sensed and amplified, that signal can be detected as receive audio.

Because a single detector cannot adequately distinguish the sum and

difference mixing frequencies, quadrature local oscillators (e.g. those 90

degrees apart at RF) are used to produce a pair of audio signals, “I”

(in-phase) and “Q” (quadrature) which may then be used later on to

distinguish between the sum and difference signals via the “phasing

method” via mathematical methods in the MCU.

The function of the “switch” in the above description is provided by U15

with the “storage capacitors”being C68 and C69. Low noise op amp U16

provides both gain low-pass filtering to the signals from the QSD before

being sent to the UI board for processing.

TX Quad Preamp and TX Mixer:

For transmitting, the I and Q signals from the UI board are filtered and

buffered by U19 which also provides a set of 180 degree (differential)

signals for both I and Q. The two outputs from each channel are

further-boosted to a low-impedance source using LM386 audio amplifiers,

U20-U23.

The high-level, low-impedance differential audio signals are applied to U17,

a switch which like U15 in the receive QSD, is driven at the operating

(transmit) frequency – but in “reverse”. Instead of RF input producing audio

on the output of the switch, audio is applied to the switch and

double-sideband audio appears on the RF side of the each switch.

Were it not for the fact that both our local oscillator and our audio were

produced in quadrature already, we would end up with double-sideband

signals on the output of our mixer, but due to the math involved in the

“phasing method” the undesired signals cancel out in the mixer, yielding

only a single set of signals on the output of T4, the “TX_MIX” line which is

then passed to the Bandpass Filter.

TX Power Amplifier:

The transmit signals from the mixer, having already passed through the

bandpass filter, is first applied to T5 to produce a differential signal. With

their drive signals 180 degrees apart, Q3 and Q4 each amplify the input

signal, boosting its voltage significantly from a few hundred millivolts on

the input to several volts on their respective collectors.

Note: In the original diagram the bias is applied continuously to Q3 and Q4

causing a continuous collector current of 50-70mA to flow, even when the

transceiver is off. In the “Board Modifications” document there is

information on a modification to change this to a “keyed” bias so that Q3

and Q4 are only biased when the PTT line is active.

Ailunce HS1 User ’s Manual

71

This signal – at a fairly high impedance – is then applied, via DC blocking

capacitors C99 and C100, to the final RF amplifier transistors Q5 and Q6,

N-channel RF power FETs. The drain voltage for these FETs is provided by

T6 which is bifilar wound with the winding phased such that RF “ground”

(DC input) of one of the FET's connections is physically the same as the RF

“hot” side of the other. RF output is extracted via T7, an RF transformer

with a 2:3 impedance transformation with the “low” side of the impedance

being connected to Q5 and Q6.

DC bias for the FETs is supplied via U18 which, when PTT is active, with

the voltage being set via a D/A output from the MCU from the line

“PA_BIAS”. This line varies from 0-3.3 volts, but the intrinsic 1.25 volt

offset of U18 means that the actual voltage appearing on its pin 1 may be

varied from 1.25 to 4.55 volts, nominal.

UI Board:

MCU power and clocks:

The heart of the HS1 transceiver is the MCU, an STM32F405-VG or

STM32F407-VG (either one will work), a processor with a Cortex ARM M4

with hardware floating point, internally clocked at 168 MHz with 1

Megabyte of flash program memory and 192 kbytes of SRAM. Using either

a 20 MHz TCXO (U5) or a 20 MHz crystal (Y1) (builder's option) the

processor's clock, and the clock for the audio codec are synthesized: This

clock source has nothing to do with the main RF synthesizer frequency or its

accuracy except by the accuracy of the sample rate of the audio codec.

The MCU has its own power source, derived from the +5 volt supply

(UI_5V) from U6, isolated via R45, R46 and C96. This added regulator and

isolation were found to be necessary as the MCU's current requirements

caused a very slight modulation of the main 3.3 volt rail in the original

design which resulted in circulating currents in the ground of the HS1 and

thus appearing at the millivolt level (or lower) in the receive I and Q audio

lines: It was only by adding this extra regulator and the R/C filtering and

isolating this “noise” to the physical vicinity of the MCU that his noise

source was eliminated.

The presence of jumper P6 should be noted. It is used only upon the initial

• It is necessary that an additional resistor of between 1k and 10k be

placed across C96 in order to establish a minimum DC current load for

U18. Because FETs draw no gate current, it is possible that normal

device leakage current of the FET and/or U18 can cause this voltage to

exceed the set voltage if there is no current load present.

• In addition to the parallel resistance mentioned above, additional

capacitance is required in parallel with C96 to assure that U18

operates in a stable mode and does not oscillate, causing distorted

transmit signals. A minimum of a 22 uF Tantalum (or 100 uF

electrolytic) is what is needed to assure stability of this circuit

under all operating conditions!

• When ordering final FETs for the HS1, it is recommended that one

order “matching” FETs if possible. If the option of “matched” devices

is not available, it is recommended that “extra” devices be obtained

Notes:

and then two devices selected for closest-matching threshold voltages.

Because there is only one bias setting, these FETs should be “matched”

in terms of DC threshold voltage. This voltage may be easily

determined with the use of one of those <$20US universal “component”

testers, or a simple test circuit constructed to ascertain this threshold.

Ailunce HS1 User ’s Manual

72

installation of the HS1 bootloader, replacing the factory-installed bootloader.

After this has been successfully completed, P6 should be removed and not

needed again.

On version 0.4 of the RF board U7, an accommodation to allow the addition

a serial EEPROM has been provided. As of this firmware version, it is not

supported and it need not be installed.

Front Panel User Controls and RF Board Interface and USB:

The main user interface consists of four rotary encoders and seventeen

pushbuttons, all interfaced directly to the MCU's IO lines utilizing onboard

pull-ups. Each of these lines has included a bypass capacitor, both for

debounce purposes and also to provide a degree of RF immunity as well as

to reduce the probability of spurious RF emissions from those lines.

Also controlled by the interface are two LEDs. The Green LED indicates

that the MCU is operational and powered up while the Red LED is used to

show that the PTT (transmit) is active.

For the newer boards (Version 0.3 and up) the typical LCD used, the

HY28B, has a parallel interface that allows for the direct mapping of the

display's RAM (256kbytes) to the memory management peripheral of the

MCU allowing objects to be drawn on the screen simply by writing to the

appropriate memory location.

For older boards that use the HY28A, the interface to the LCD is based on

the SPI (serial) interface which is very much slower, but a separate set of

optimized display routines have been implemented in the HS1's code to

maximize speed and usability.

Pin 40 of the LCD (“BL_CTRL”) is used to blank the backlight and it is also

PWM (Pulse-Width Modulated) controlled to provide a brightness control of

the LCD to save power. Because the use of PWM necessarily modulates the

LCD's power supply, additional filtering in the form of C74a and R35a have

been added to keep this modulation energy from finding its way onto the

main “UI_5V” bus, onto the ground bus and into the low-level audio. At the

present time the backlight dimming PWM signal is generated in software

and there are some operational conditions (e.g. when transmitting using CW)

that the brightness can vary due to disruptions in this waveform.

The “RF Board Interface and USB” provides the pathways from the MCU to

the RF board. Of note are the SPI signals “SCL” and “SDA” and resistors

R47 and R48: These resistors reduce the slew rate of the falling edge of the

serial data from the MCU to the Si570 and the temperature sensor,

minimizing the generation of broadband RF energy and a period “tick” that

may result.

Also included is J11, the USB Dfu connector used for programming and J10,

the full-sized USB connector which is reserved for future use with other

peripherals. Connector P8 is also provided, but its use is limited for

hardware debug using the appropriate development tools.

Codec and Audio Switching:

The receive I and Q audio from U16 on the RF board is fed into U3 which is

used to select either the receive mixer or the “Line In” jack as there is only

one A/D converter on the HS1. In receive mode,U3 always routes the audio

from U16 to the “LLINEIN” and “RLINEIN” pins of U1, the codec where

the audio is digitized and made available to the MCU via a dedicated SPI

interface.

Ailunce HS1 User ’s Manual

73

After being processed by the MCU, the receive audio is sent back to U1 via

the SPI interface and it is output on the output pins. On this particular codec,

there are two sets of outputs: “LHPOUT” and “RHPOUT” which have

adjustable output levels and “LOUT” and “ROUT” which have fixed levels

– but they both carry the exact same audio.

Speaker audio is output via the “LHPOUT” line to U2, an LM386 audio

amplifier while the “Line Out” audio is output from the “RHPOUT” line.

Because they are independently adjustable, their levels may be varied and

muted as needed – via the volume control in the case of the speaker for

receive and muted during transmit for both the speaker and Line Out.

In transmit mode, there are two possible sources of transmit audio: If the

“Line In” mode is selected the codec is configured to use audio from its two

“Line In” pins as U3 always routes the signal from the “Line In” jack to

these pins when in transmit mode. If the “Microphone Input” is selected, the

codec uses only the “MICIN” pin for its audio source. The selected audio is

then digitized and sent to the MCU to be processed.

The processed audio to be transmitted is then sent back to the codec to be

converted back to analog and it is output on the “LOUT” and “ROUT” pins.

When in transmit mode analog switch U3a is closed, allowing the signal

from these two pins to be sent to the RF board in the “AUDIO_OUT_I” and

“AUDIO_OUT_Q” lines.

On UI boards 0.3 and earlier, switch U3a was absent, which posed a

problem when in receive mode. Because the receive audio is always present

on the “LOUT” and “ROUT” pins, receive audio was also sent on the

“AUDIO_OUT_I” and “AUDIO_OUT_Q” lines to the RF board,

amplified,and applied to the transmit QSD mixer, U17. At high receive

volumes and with strong signals the audio going into U17 exceeded the 5

volt supply voltage of that device causing it to falsely turn on, creating

onfrequency spurious signals which, in turn, resulted in distorted feedback in

the receiver. The addition of U3a permits the blocking of these signals when

in receive mode, eliminating this problem entirely.

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ATTENTION!

Before using this radio, read this guide which contains

important operating instructions for safe usage and RF energy

awareness and control for compliance with applicable standards

and regulations.

RF ENERGY EXPOSURE AND PRODUCT SAFETY GUIDE FOR PORTABLE TWO-WAY RADIOS

This two-way radio uses electromagnetic energy in the radio frequency (RF) spectrum to provide communications between two or more users over a distance. RF energy, which when used improperly, can cause

biological damage.

All Retevis two-way radios are designed, manufactured, and tested to ensure they meet government-established RF exposure levels. In addition, manufacturers also recommend specific operating instructions to users of

two-way radios. These instructions are important because they inform users about RF energy exposure and provide simple procedures on how to control it.

Please refer to the following websites for more information on what RF energy exposure is and how to control your exposure to assure compliance with established RF exposure limits:http://www.who.int/en/

Local Government Regulations

When two-way radios are used as a consequence of employment, the Local Government Regulations requires users to be fully aware of and able to control their exposure to meet occupational requirements. Exposure

awareness can be facilitated by the use of a product label directing users to specific user awareness information. Your Retevis two-way radio has a RF Exposure Product Label. Also, your Retevis user manual, or

separate safety booklet includes information and operating instructions required to control your RF exposure and to satisfy compliance requirements.

Radio License

Governments keep the radios in classification, business two-way radios operate on radio frequencies that are regulated by the local radio management departments (FCC, ISED, OFCOM, ANFR, BFTK,

Bundesnetzagentur...).To transmit on these frequencies, you are required to have a license issued by them. The detailed classification and the use of your two radios, please contact the local government radio

management departments.

Use of this radio outside the country where it was intended to be distributed is subject to government regulations and may be prohibited.

Unauthorized modification and adjustment

Changes or modifications not expressly approved by the party responsible for compliance may void the user’s authority granted by the local government radio management departments to operate this radio and should

not be made. To comply with the corresponding requirements, transmitter adjustments should be made only by or under the supervision of a person certified as technically qualified to perform transmitter maintenance

and repairs in the private land mobile and fixed services as certified by an organization representative of the user of those services.

Replacement of any transmitter component (crystal, semiconductor, etc.) not authorized by the local government radio management departments equipment authorization for this radio could violate the rules.

FCC Requirements:

This device complies with part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. (Licensed radios are applicable);

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•Disposal

The crossed-out wheeled-bin symbol on your product, literature, or packaging reminds you that in the European Union, all electrical and electronic products, batteries, and accumulators (rechargeable batteries)

must be taken to designated collection locations at the end of their working life. Do not dispose of these products as unsorted municipal waste. Dispose of them according to the laws in your area.

IC Requirements:

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (Other devices are applicable)

(1) This device may not cause harmful interference, and

(2) this device must accept any interference received, including interference that may cause undesired operation.

NOTE: This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful

interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual,

may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his

own expense.

CE Requirements:

•(Simple EU declaration of conformity) Shenzhen Retevis Technology Co., Ltd. declares that the radio equipment type is in compliance with the essential requirements and other relevant provisions of RED Directive

2014/53/EU and the ROHS Directive 2011/65/EU and the WEEE Directive 2012/19/EU; the full text of the EU declaration of conformity is available at the following internet address: www.retevis.com.

•Restriction Information

This product can be used in EU countries and regions, including: Belgium (BE), Bulgaria (BG), Czech Republic (CZ), Denmark (DK), Germany (DE), Estonia (EE), Ireland (IE), Greece (EL), Spain (ES), France (FR),

Croatia (HR), Italy (IT), Cyprus (CY), Latvia (LV), Lithuania (LT), Luxembourg (LU), Hungary (HU), Malta (MT), Netherlands (NL), Austria (AT), Poland (PL), Portugal (PT), Romania (RO), Slovenia (SI), Slovakia

(SK), Finland (FI), Sweden (SE) and United Kingdom (UK).

For the warning information of the frequency restriction, please refer to the package or manual section.

Licence-exempt radio apparatus

This device contains licence-exempt transmitter(s)/receiver(s) that comply with Innovation, Science and Economic Development Canada’s licence-exempt RSS(s). Operation is subject to the following two conditions:

(1) This device may not cause interference.

(2) This device must accept any interference, including interference that may cause undesired operation of the device.

Le présent appareil est conforme aux CNR d’Industrie Canada applicables aux appareils radio exempts de licence. L’exploitation est autorisée aux deux conditions suivantes :

(1) l’appareil ne doit pas produire de brouillage;

(2) l’utilisateur de l’appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d’en compromettre le fonctionnement.

RF Exposure Information

•DO NOT operate the radio without a proper antenna attached, as this may damage the radio and may also cause you to exceed RF exposure limits. A proper antenna is the antenna supplied with this radio by the

manufacturer or an antenna specifically authorized by the manufacturer for use with this radio, and the antenna gain shall not exceed the specified gain by the manufacturer declared.

•DO NOT transmit for more than 50% of total radio use time, more than 50% of the time can cause RF exposure compliance requirements to be exceeded.

•During transmissions, your radio generates RF energy that can possibly cause interference with other devices or systems. To avoid such interference, turn off the radio in areas where signs are posted to do so.

•DO NOT operate the transmitter in areas that are sensitive to electromagnetic radiation such as hospitals, aircraft, and blasting sites.

•Portable Device, this transmitter may operate with the antenna(s) documented in this filing in Push-to-Talk and body-worn configurations. RF exposure compliance is limited to the specific belt-clip and accessory

configurations as documented in this filing and the separation distance between user and the device or its antenna shall be at least 2.5 cm.

•Mobile Device, during operation, the separation distance between user and the antenna subjects to actual regulations, this separation distance will ensure that there is sufficient distance from a properly installed

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Hand-held Mode

• Hold the radio in a vertical position with the microphone (and other parts of the radio including the antenna) at least 2.5 cm (one inch) away from the nose or lips. The antenna should be kept away from the

eyes. Keeping the radio at a proper distance is important as RF exposure decreases with increasing distance from the antenna.

Phone Mode

Small Parts. Not for children under 3 years.

externally-mounted antenna to satisfy the RF exposure requirements.

•Occupational/Controlled Radio, this radio is designed for and classified as “Occupational/Controlled Use Only”, meaning it must be used only during the course of employment by individuals aware of the hazards, and

the ways to minimize such hazards; NOT intended for use in a General population/uncontrolled environment.

•General population/uncontrolled Radio, this radio is designed for and classified as “General population/uncontrolled Use”.

RF Exposure Compliance and Control Guidelines and Operating Instructions

To control your exposure and ensure compliance with the occupational/controlled environment exposure limits, always adhere to the following procedures.

Guidelines:

•User awareness instructions should accompany the device when transferred to other users.

•Do not use this device if the operational requirements described herein are not met.

Operating Instructions:

•Transmit no more than the rated duty factor of 50% of the time. To Transmit (Talk), push the Push to Talk (PTT) button. To receive calls (listen), release the PTT button. Transmitting 50% of the time, or less, is

important because the radio generates measurable RF energy exposure only when transmitting in terms of measuring for standards compliance.

•Transmit only when people outside the vehicle are at least the recommended minimum lateral distance away from a properly installed according to installation instructions, externally mounted antenna.

•When operating in front of the face, worn on the body, always place the radio in a Retevis approved clip, holder, holster, case, or body harness for this product. Using approved body-worn accessories is important

because the use of Non-Retevis approved accessories may result in exposure levels, which exceed the IEEE/ICNIRP RF exposure limits.

•When placing or receiving a phone call, hold your radio product as you would a wireless telephone. Speak directly into the microphone.

Electromagnetic Interference/Compatibility

NOTE: Nearly every electronic device is susceptible to electromagnetic interference (EMI) if inadequately shielded, designed, or otherwise configured for electromagnetic compatibility.

Avoid Choking Hazard

Turn off your radio power in the following conditions:

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WARNING

•Turn off your radio before removing (installing) a battery or accessory or when charging battery.

•Turn off your radio when you are in a potentially hazardous environments: Near electrical blasting caps, in a blasting area, in explosive atmospheres (inflammable gas, dust particles,

metallic powders, grain powders, etc.).

•Turn off your radio while taking on fuel or while parked at gasoline service stations.

To avoid electromagnetic interference and/or compatibility conflicts

•• Turn off your radio in any facility where posted notices instruct you to do so, hospitals or health care facilities (Pacemakers, Hearing Aids and Other Medical Devices) may be using

equipment that is sensitive to external RF energy.

•Turn off your radio when on board an aircraft. Any use of a radio must be in accordance with applicable regulations per airline crew instructions.

Protect your hearing:

WARNING

• Use the lowest volume necessary to do your job.

• Turn up the volume only if you are in noisy surroundings.

• Turn down the volume before adding headset or earpiece.

• Limit the amount of time you use headsets or earpieces at high volume.

• When using the radio without a headset or earpiece, do not place the radio's speaker directly against your ear

• Use careful with the earphone maybe possible excessive sound pressure from earphones and headphones can

cause hearing loss

Note: Exposure to loud noises from any source for extended periods of time may temporarily or permanently

affect your hearing. The louder the radio's volume,

the less time is required before your hearing could be affected. Hearing damage from loud noise is sometimes

undetectable at first and can have a cumulative effect.

Avoid Burns

WARNING

Antennas

•Do not use any portable radio that has a damaged antenna. If a damaged antenna comes into contact with the skin when the radio is in use, a minor burn can result.

Batteries (If appropriate)

•When the conductive material such as jewelry, keys or chains touch exposed terminals of the batteries, may complete an electrical circuit (short circuit the battery) and become hot to

cause bodily injury such as burns. Exercise care in handling any battery, particularly when placing it inside a pocket, purse or other container with metal objects

Long transmission

•When the transceiver is used for long transmissions, the radiator and chassis will become hot.

Safety Operation

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78

WARNING

Forbid

•Do not use charger outdoors or in moist environments, use only in dry locations/conditions.

•Do not disassemble the charger, that may result in risk of electrical shock or fire.

•Do not operate the charger if it has been broken or damaged in any way.

•Do not place a portable radio in the area over an air bag or in the air bag deployment area. The radio may be propelled with great force and cause serious injury to occupants of the

vehicle when the air bag inflates.

To reduce risk

•Pull by the plug rather than the cord when disconnecting the charger.

•Unplug the charger from the AC outlet before attempting any maintenance or cleaning.

•Contact Retevis for assistance regarding repairs and service.

•The adapter shall be installed near the equipment and shall be easily accessible

Approved Accessories

WARNING

•This radio meets the RF exposure guidelines when used with the Retevis accessories supplied or designated for the product. Use of other accessories may not ensure compliance with

the RF exposure guidelines and may violate regulations.

•For a list of Retevis-approved accessories for your radio model, visit the following website: http://www.Retevis.com