Page 1
Equipment Review
Copyright RSGB 2015, Reproduced here with kind permission.
Icom IC-7851 HF &
50MHz transceiver
A new flagship is born: the current market
leader in terms of performance
PHOTO 1: IC-7851 front view.
INTRODUCTION. In 2004, Icom launched
their IC-7800 top-of-the-range agship
transceiver, raising the bar on what
was available at that time in terms of
performance and level of built-in features.
It has remained their agship for the past
10 years and is still one of the top-ight
transceivers available today. Icom has now
unveiled its successor, the IC-7851. Based
heavily on the previous model, it adopts
signicant technological advances to further
improve performance and enhance the high
level of features that are incorporated.
SUMMARY OF KEY CHANGES AND
SIMILARITIES. At a rst glance, the
outward appearance of the IC-7851 is
very similar to the IC-7800. The size and
weight are the same, the styling and front
panel layout are the same, but the rear
panel shows a number of changes. The
same RF, control and accessory interfaces
are provided but the RF cable links are
no longer needed. Improved support is
provided for computer connected equipment
and peripherals but the RS-232 connector
has been removed. The CI-V interface has
been retained but the CT-17 level converter
is required if RS-232 is needed. The RF
architecture is essentially the same as with
the IC-7800 but a new design for the local
oscillators results in signicantly improved
noise characteristics. The RF functions and
transmit power level are the same but there
is a greater choice of narrow roong lters.
It is in the DSP area where other major
advances have been made. Three DSP
devices are employed instead of the four
36
Peter Hart, G3SJX
used in the IC-7800 but the new devices
are considerably faster and more powerful.
The scope display has been redesigned,
offering a dual display for simultaneous
monitoring of both receivers, higher speeds
with better sensitivity and resolution.
Spectrum and waterfall displays, audio
spectrum and waveform, and mouse click
tuning are all provided.
Data modes now include PSK63.
Compact Flash card support has been
replaced by SD card and all settings and
message stores can be saved to SD or USB
ash drive. The voice recorder function
has been expanded to allow continuous
recording of receive and transmit audio,
limited only by external memory size, and
transmit message stores provide eight
channels on all operating modes. The setup
screens have been greatly expanded and
many other little tweaks and additions have
been incorporated into the various operating
functions.
BASIC FUNCTIONS. The IC-7851 is a
mains powered base station radio covering
LF, MF, HF and 6m. Measuring 425mm
(w) x 149mm (h) x 435mm (d) and
weighing a heavy 23.5kg, it is also supplied
with attachable front facing handles for
rack mounting operation or carriage. It
incorporates two totally independent and
identical receivers each tuning continuously
from 30kHz to 60MHz. The transmitter is
rated at 200W output and is enabled only
within the amateur bands. The version sold
in Europe also transmits in the 136kHz
band but only at a level of –20dBm via the
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November 2015
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e-mail: peter@sjx.freeserve.co.uk
transverter socket on the rear panel. 5MHz
operation, standard on US-sold models, can
be enabled by Icom agents.
Individual buttons select the bands with
a triple band stacking register and separate
buttons also select the modes LSB, USB,
CW, FM, AM, RTTY and PSK, with both
sidebands (normal/reverse) available on CW,
RTTY and PSK modes. There is extensive
support for data modes, including dedicated
modems and display for RTTY and PSK and
three different selectable settings for data
operation on SSB, AM and FM modes. This
enables different audio lines to be switched
between alternative accessory connectors on
the rear panel.
The extensive functions provided in
the radio are accessed in most cases
by dedicated controls rather than
multifunctional layered menus. There
are over 100 controls on the front panel.
Access to functions is straightforward and
intuitive and user setup rarely involves
more than one long button push. The
amount of information displayed on the
large LCD panel is most impressive. This
uses a 7-inch full-colour active matrix TFT
display and may also be displayed on an
external monitor via a DVI-I connector
on the rear panel. Apart from the most
informative setup screens, the display gives
a high-resolution spectrum plot, memory
data lists of various types, incoming and
outgoing RTTY/PSK data messages and two
large meters. Three different meter formats
are selectable – a very realistic analogue
lookalike needle display with excellent
resolution, an edgewise meter and a bar
meter. In addition, a multifunction meter
may be selected, which displays seven
items of transmit data simultaneously
including heatsink temperature.
The rear panel carries an enormous
number of connectors. There are four
antenna sockets that may be selected from
the front panel or automatically assigned
according to band. The receive path for both
receivers allows for receive-only antennas,
external receivers or external in-line lters.
The usual accessory sockets are duplicated
to allow more than one data terminal unit,
linear amplier or external auto ATU to be
connected simultaneously. A keyboard,
RadCom
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Copyright RSGB 2015, Reproduced here with kind permission.
November 2015
Peter Hart, G3SJX
RadCom
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e-mail: peter@sjx.freeserve.co.uk
mouse and external ash memory may
be connected via two USB-A connectors
and PC interfacing via a USB-B connector
or Icom CI-V interface. An Ethernet LAN
connector is provided for remote access,
there are S/P DIF bre optic digital
audio jacks, sockets to connect external
meter readout and a keypad for transmit
memory stores. There is a transverter
drive capability giving about -20dBm on
transmit and switching for linear ampliers
accommodates a wide range of switching
voltages and currents together with ALC.
Twin key jacks are tted, one on the front
panel and the other on the rear.
Each radio is provided with a
comprehensive instruction manual
contained within a ring binder and with
circuit diagrams and a PDF version of the
manual on CD-ROM.
RADIO DESIGN AND ARCHITECTURE.
The receivers used in the IC-7851 adopt a
double superhet architecture with a rst IF
of 64.455MHz (A receiver) or 64.555MHz
(B receiver) and then converting down to a
second IF of 36kHz with an image rejection
mixer to feed the DSP for all further
processing. All channel ltering is performed
at the 36kHz IF by DSP. Four selectable
roong lters are incorporated at the rst
IF in both receiver paths with bandwidths
of 15, 6, 3 and 1.2kHz. The 1.2kHz lter
is a new design and a calibration routine
is built in to optimise the lter passband.
This operates by slightly shifting the rst
and second local oscillators to position the
lter passband at the correct point and allow
for any variation due to ageing or other
factors. Calibration is simply performed
automatically or manually as needed.
Each receiver uses a total of 13 switched
front end lters to provide the signal
frequency ltering and a separate sharply
tuned preselector, the Digi-Sel unit, may
also be enabled. Mechanical relays are used
entirely for signal switching in the front end
avoiding the use of switching diodes that
can generate intermodulation products with
very high level signals. A separate front
end is used for frequencies above 30MHz.
The rst local oscillator uses a DDS / PLL
arrangement optimised for low noise. The
transmit path adopts triple conversion,
interspersing a 455kHz IF between the
36kHz DSP generated transmit signal and
the 64.455MHz nal IF. The MOSFET
PA operates from a 48V supply for good
linearity.
Three separate 32-bit oating point
DSP units are used with 24-bit AD/DA
converters. Two are used for the receivers
and the transmit signal and these are
powerful 2400 MFLOP devices clocked
at 393MHz. The third is dedicated to the
spectrum scope, a 2250 MFLOP device
clocked at 370MHz. AGC is applied mainly
PHOTO 2: The rear panel carries an enormous number of connectors.
within the DSP but an auxiliary loop
reduces the gain of the rst IF amplier on
strong signals. An ultra high stability oven
controlled crystal oscillator is used for the
synthesiser reference signal source. This
is specied as stable to within ±0.05ppm
over the operating temperature range of
the radio, which equates to just 2.5Hz at
50MHz. This 10MHz reference frequency
output is also available on the back panel
of the radio for other uses or alternatively an
external reference can also be used.
The radio is constructed on fully
screened circuit boards housed in a
substantial compartmentalised diecast
chassis. A large internal nned heatsink
cools the power amplier and is blown by
two internal fans. Considering the size of the
radio, a single very small speaker is tted,
just 60mm diameter. However, it is a hi-
style unit tted into an acoustic box and
gives better than average quality with no
unwanted rattles and resonances that result
from the usual open mounted unit.
quickly stored and recalled by a simple key
press, on the basis of last-in, rst-out. RIT
and transmitter independent tuning operate
over a range of ±9.99kHz and various scan
modes are implemented.
All controls for the two receivers are
duplicated and independent and logically
laid out. The receiver paths are kept
separate right through to the audio output
with left and right channels on stereo
headphones or external speakers, or
combined for the internal speaker. The
usual receiver functions are provided. The
receiver front end conguration may be
optimised to suit different requirements with
two selectable preampliers, seven levels
of signal attenuation, RF gain and squelch
controls. Preamp 1 has a gain of about
12dB and preamp 2 about 20dB. This
higher gain preamp is primarily intended for
use on the higher frequency bands but can
be useful on the lower frequencies when
low output receive antennas are used such
as small loops or Beverages.
To improve further the front end signal
RECEIVER FEATURES. The radio is
tted with two VFOs, one controlling each
receiver, and two tuning knobs. The main
is 55mm in diameter and the sub is 35mm
in diameter. This is the only difference
between the two receivers. The transmitter
uses the main VFO for normal operation and
the sub VFO for split frequency working. A
quick split feature enables split frequency
operation and equalises the VFOs. Tuning
is in 1Hz steps at 500Hz per revolution or
handling with very strong out of band
signals experienced for example in a
multi-multi contest site, a sharply tuned
preselector termed Digi-Sel may be enabled
at the receiver input covering frequencies
from 1.5 to 30MHz. Two units are tted,
one in each receiver path, using relay
switched capacitors and inductors to track
automatically the tuning of the receiver.
A front panel control provides ne peaking
if needed.
10Hz steps at 5kHz per revolution. A faster
rate of selectable kHz step sizes enables
more rapid navigation and auto speed-up
is selectable for fast sustained tuning. The
frequency may also be entered directly
from the band keypad and a ¼ tuning
rate function is selectable for ne-tuning
data signals. An auto-tune feature may be
enabled for CW and AM modes.
101 memory channels are included with
the usual access facilities. Memories can be
tagged with a 10 character alphanumeric
label. The memory list screen is very
convenient for scrolling through and
searching memories and displays up to 15
memory contents at one time. A separate
memo-pad feature allows frequencies to be
FILTERS. With the exception of the roong
lters, all ltering, demodulation and audio
processing functions are implemented in
DSP. The channel ltering provides 41
different passband widths on SSB, CW and
PSK from 50Hz to 3600Hz, 32 passband
widths on RTTY (50-2700Hz) and 50
passband widths on AM (200Hz-10kHz).
On FM three bandwidths are provided (7,
10 and 15kHz). Three separate bandwidths
are immediately available for each mode
selectable by a simple push of a front panel
key, from the available menu of bandwidths.
In addition, two lter proles are selectable
on CW and SSB modes, a sharp prole
with a at passband and a soft prole with
Equipment Review
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Equipment Review
Copyright RSGB 2015, Reproduced here with kind permission.
Peter Hart, G3SJX
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November 2015
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e-mail: peter@sjx.freeserve.co.uk
RadCom
a more rounded passband. The DSP also
provides the twin passband tuning function,
which enables the lter sides to be both
independently moved and narrowed. The
lter set-up screen on the display shows
all the lter adjustments in a friendly and
graphical way.
The AGC is also implemented by the
DSP with three separate time constants
(Fast, Mid, Slow) plus constantly variable
selectable from the front panel. These
three values may be set from a menu of 13
different values (0.1 to 6s SSB/CW) and
are set separately for all modes except FM.
The AGC can also be turned off. Two very
effective notch functions are provided in this
transceiver, both using the DSP. A manually
tuned IF notch with a depth of 70dB and
three selectable widths is included within
the AGC loop and hence does not result
in desensitising with strong carriers. An
auto-notch is implemented at AF and will
automatically attenuate several beat notes,
even if they are moving. An adjustable DSP
noise reduction system is also included and
there is a separate adjustable noise blanker
for pulse type interference such as car
ignition noise.
DSP also provides audio ltering and
shaping functions. A narrow audio peak
lter is available on CW with selectable
bandwidths and a twin peak lter sharply
tuned to the 2125Hz and 2295Hz mark
and space tones on RTTY. Extensive audio
tailoring for both receive and transmit is also
provided, with adjustable high pass and low
pass cut-offs, treble and bass shaping and
all separately adjustable for each mode.
TRANSMIT FEATURES. The IC-7851
contains a 200W power amplier adjustable
down to less than 5W. VOX, speech
processor and a transmission monitor are
provided on SSB and the transmission
lter bandwidth can be set to wide, mid
or narrow as preferred in addition to audio
frequency response tailoring. On CW there is
the usual provision for full and semi breakin with a front panel control for drop-back
delay and the keying envelope rise and fall
times are adjustable between 2 and 8ms to
accommodate both fast CW and minimum
radiated bandwidth.
The CW keyer operates over a wide range
of speeds with adjustable weighting and a
variety of keying paddle arrangements. Eight
memories will each store messages up to
70 characters in length with a provision
to send automatically incrementing serial
numbers and auto-repeat after a time delay.
The message stores are programmed in text
either from front panel controls or directly
from a PC USB keyboard connected to the
relevant rear panel socket. Messages can be
played back from front panel pushbuttons,
from the keyboard function keys or from
a custom 8-key keypad plugged into
40
PHOTO 3: Multi-function meter display.
the rear panel. Surprisingly, Icom do not
offer this keypad as an accessory, but it
is straightforward to construct your own
and details are provided in the manual.
Separate message stores are also provided
for RTTY, PSK and voice modes. For each
mode eight stores are available, access
being broadly similar to the CW store. 70
characters may be stored in each RTTY and
PSK memory and 200 seconds of audio
in each voice store. Keypad or keyboard
access is particularly convenient. The CW
and voice stores can be set to repeat after a
brief delay.
An auto ATU is built-in covering all
bands including 50MHz and matching up
to 3:1 VSWR (2.5:1 on 50MHz). Tuning
settings every 100kHz are stored to enable
rapid and accurate reselection.
DATA MODES. The IC-7851 is fully
equipped for receiving and sending RTTY,
PSK31 and PSK63 data modes as a stand-
alone unit without the need to be connected
to a PC running data mode software. A
USB keyboard needs to be connected to the
relevant rear panel socket for transmitting
messages but is not needed if used only on
receive.
When using the internal modem, the
display window is divided into two areas,
the receive contents area and the transmit
buffer area. These areas allow for 48
characters per line and, depending on
whether a wide or narrow display window
has been selected, either 14 or 8 lines in
the receive area and 3 or 2 lines in the
transmit buffer area. The wide setting is
best for any serious data operation. With
this setting the frequency readout size is
reduced and metering is displayed in bar
or edge format. Two audio spectrum tuning
indicators are provided for both RTTY and
PHOTO 4: Spectrum and audio scope displays.
PSK modes; an FFT display that shows
the amplitude of the received components
against frequency and a waterfall display
that shows this information colour coded
also against time. The twin peaks of an
RTTY signal or the narrower spread of a
PSK-31 signal can be clearly seen. For the
PSK decoder, a vector tuning indicator is
also provided to allow accurate ne tuning
of the signal, as a line for a BPSK signal or
as a cross for a QPSK signal. Both BPSK
and QPSK modes are supported.
AFC and transmit netting are provided on
PSK modes to help with ne tuning. A host
of options are also included for setting time
stamps, display colours, scope waveform
averaging, RTTY parameters such as unshift
on space and more. RTTY Log and PSK Log
enables received and transmitted data to be
stored to USB ash memory or SD card in
either text or HTML format.
AUXILIARY FEATURES. All the settings
of the radio, the contents of the various
memories and message stores, the
receive and transmit audio and data mode
messages can all be saved to USB ash
memory or an SD card. The contents can
then be used to reset the radio to the stored
settings at any time in the future. This can
be particularly useful in a multi-operator
contest or DXpedition where each operator
can store their own preferred settings or
CQ calls in their own voice and instantly
congure the radio for the duration of their
operating period.
The IC-7851 includes a built-in digital
voice recorder. As well as providing message
stores on transmit, the voice recorder also
stores the receive and transmit audio. There
are essentially two modes of operation.
Up to 30 seconds of receive audio is
always stored for both receivers and is
available for instant replay without any prior
setting needed. Hence any badly copied
information can be replayed over and over
again if necessary. In the second mode,
the audio is recorded to external memory,
SD or USB, limited in time only by the
amount of available memory. Four hours
of audio occupy less than one gigabyte.
Both receivers are recorded as left and right
channels of a .WAV le. It can be played
back on the radio or externally on a PC.
The spectrum scope in the IC-7851
is a signicant enhancement over the
earlier radio. It has 100dB of displayed
dynamic range and an additional associated
waterfall. A dual mode can selected to cover
both receivers on separate displays. These
may be side by side or one above the other
and all settings are independent. There are
two modes of operation. The centre mode
will display the spectrum on either side of
the on-tune frequency with spans selectable
from ±2.5kHz to ±500kHz. The Fix mode
will display the spectrum between two
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Equipment Review
Copyright RSGB 2015, Reproduced here with kind permission.
Peter Hart, G3SJX
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November 2015
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e-mail: peter@sjx.freeserve.co.uk
RadCom
xed points, these points being separately
programmable for each band. In both modes
there are a number of settings that select
sweep speed, colours, VFO markers, peak
hold etc. The spectrum scope can be used
in conjunction with other display screens by
using the mini-scope mode.
When a mouse is connected, a cursor
appears on the spectrum display and the
radio can be set to the selected frequency
by left-clicking or tuning by dragging. Right
clicking will temporarily change frequency,
returning to the original frequency when the
button is released. This is useful if you just
want to check a signal that you observe but
want to retain your working frequency.
An audio scope display is also included.
This shows the audio spectrum with
associated waterfall and a waveform display.
This functions on both receive and transmit
and can help in setting up the transmitter
audio levels.
Other features include calendars,
clocks and timers of various types, a voice
synthesiser for audible readout of frequency,
mode and S-meter level, a CTCSS tone
encoder and decoder for repeater access and
tone squelch operation, and quick access
splits separately programmable for HF and
50MHz repeater operation. When used with
a transverter, the displayed frequency can be
offset up to 99.999MHz in 1kHz steps but
this is insufcient to allow the full transverted
frequency to be displayed above 100MHz.
When Icom releases rmware updates
these are installed by transferring the data
le to the radio using USB or SD card. PC
control of the radio uses the CI-V interface in
conjunction with the CT-17 level converter
and the command set is described in the
manual. Full remote control of the radio via a
LAN, Wi-Fi or the internet uses the Ethernet
interface to a router in conjunction with the
RS-BA1 software package running on the PC
at the remote end. Client software is included
in the IC-7851 rmware so a PC is not
needed at the radio end of the link. Control
and audio are both transferred.
MEASUREMENTS. The full set of
measurements is given in the table. Two
preampliers are selectable across the whole
tuning range of the radio although a different
front end with associated preampliers is
selected above 30MHz. Sensitivity gures
are excellent and hold well down into the
LF region, achieving less than 0.5µV at
50kHz. The 6kHz, 3kHz and 1.2kHz roong
lters reduce sensitivity by 1, 2 and 7dB
respectively but only with the preamplier off.
Digi-Sel adds negligible loss. Dual receiver
operation (dual watch) reduces sensitivity
very slightly. The S-meter calibration is the
same on all modes and is very linear, holding
closely to 2.5dB per S-point from S1 to S9
and then within 1dB linearity up to 60dB
over S9.
42
PHOTO 5: IC-7851 RTTY decoder display.
The rejection of all images and IFs was
exceptionally good, in excess of 100dB.
Apart from a buzzing sound around 75kHz
and its harmonics at LF the receiver is
exceptionally clean and clear of other
spurious responses. The AGC response
was very clean but a brief hole was
observed in the attack characteristic.
The third order intercept measured
with 50kHz generator spacings exceeded
+40dBm over most of the HF range,
yielding dynamic ranges in excess of
110dB on SSB with 2.4kHz bandwidth.
On CW with 500Hz bandwidth even
higher dynamic ranges are achieved
and still measure over 100dB at 1kHz
spacing, well inside the roong lter
bandwidth. Inband linearity with 200Hz
spaced tones also showed exceptionally
good performance and audio noise and
distortion was low.
Reciprocal mixing gures also showed
outstanding results. Phase noise close-in is
some 20 to 30dB better than the IC-7800
and beats other top-end radios currently
on the market. The new synthesiser
design certainly lives up to its claims.
Low phase noise allowed the IF lter
skirts to be measured down to the –80dB
level with relative ease. These showed
a clean response with tight skirts. Front
end blocking was in excess of +20dBm
with the preamp off, about +15dBm
with preamp 1 and about +4dBm with
preamp 2. Overall, the strong signal results
position this radio as the current market
leader in terms of performance.
The transmit power output was well
up to specication and the metered power
level was very accurate above 20W. The
ATU introduced an additional loss of about
5 to 10%. Wideband distortion products
on SSB fell away rapidly and the speech
compressor made little difference to the
distortion levels. The CW rise and fall
times are adjustable and clean with low
character distortion. Character shortening
was about 15% at 40wpm with full breakin but no shortening with semi break-in.
No rst character shortening or power
overshoot at low power levels was seen
and with full break-in, listening between
characters at 30wpm is just possible. An
adjustable delay is provided to allow for
linear amplier switching. On AM, carrier
levels are set correctly and modulation is
clean at all power levels but the carrier
takes 0.5s to stabilise on pressing the
PTT. On data modes, receive to transmit
switching times are limited as it takes
50ms for the transmit power level to ramp
up to maximum. Transmit wideband noise
is better than most radios and indeed only
just behind the Elecraft K3, the current top
performer in this respect. Surprisingly, the
noise is slightly higher at low power levels,
CW key-up or SSB with zero modulation.
ON THE AIR PERFORMANCE. In
operation the IC-7851 is very similar to
the IC-7800. Despite having so many
features and controls, it is very easy and
intuitive to use. The controls are where
you would expect to nd them and the
main and sub receiver controls are closely
associated, unlike some other top end
radios. The display is excellent, crisp and
clear, and the various access and set-up
screens most helpful and informative.
The radio performed impeccably in
both weak signal and high-level crowded
conditions. Audio quality was excellent
on all modes and the various IF lters,
notches, noise reduction and other
functions all performed extremely well.
I could nd little to fault on any of the
features. The memories, message stores,
keyers etc all functioned very well. Built-in
operation on data modes was effective,
particularly for casual operation, although
the more serious user will generally
prefer the extra convenience of PC based
applications. The scope screen with the
extra waterfall and audio functions is a big
improvement over earlier Icom models.
One of the more useful functions is the
ability to set the frequency from the scope
display using a mouse and in particular
right-clicking to temporarily checkout an
off-channel signal observed on the display.
On transmit, the radio runs quite cool
and the fans are very quiet. The CW
transmission was narrow with clean QSK
operation. Quality reports on SSB with
the HM-36 hand microphone were good.
Similarly the SM-50 desktop microphone
showed good audio quality, particularly
with the low cut button pressed, but this
microphone was rather susceptible to
acoustic handling noise.
CONCLUSIONS. The IC-7851 is a worthy
successor to the IC-7800. At the top of the
performance league with an unsurpassed
set of well-implemented features and ease
of use, it is a most impressive radio. Priced
at around £9,000 it is aimed at the serious
enthusiast who wants nothing but the best.
ACKNOWLEDGEMENTS. I would like to
thank Icom (UK) Ltd for the loan of the
equipment.
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Copyright RSGB 2015, Reproduced here with kind permission.
November 2015
Peter Hart, G3SJX
RadCom
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e-mail: peter@sjx.freeserve.co.uk
Equipment Review
ICOM IC-7851 MEASURED PERFORMANCE
RECEIVER MEASUREMENTS
---------------SENSITIVITY SSB 10dB s+n:n--------------- ----------INPUT FOR S9----------
Frequency Preamp off Preamp 1 Preamp 2 Pre off Preamp 1 Preamp 2
1.8MHz 0.4µV (-115dBm) 0.1µV (-127dBm) 0.08µV (-129dBm) 56µV 18µV 8µV
3.5MHz 0.4µV (-115dBm) 0.11µV (-126dBm) 0.1µV (-127dBm) 50µV 16µV 8µV
7MHz 0.35µV (-116dBm) 0.1µV (-127dBm) 0.08µV (-129dBm) 50µV 16µV 7µV
10MHz 0.35µV (-116dBm) 0.1µV (-127dBm) 0.08µV (-129dBm) 50µV 16µV 8µV
14MHz 0.4µV (-115dBm) 0.13µV (-125dBm) 0.1µV (-127dBm) 56µV 16µV 8µV
18MHz 0.45µV (-114dBm) 0.11µV (-126dBm) 0.09µV (-128dBm) 63µV 18µV 9µV
21MHz 0.45µV (-114dBm) 0.11µV (-126dBm) 0.09µV (-128dBm) 56µV 16µV 9µV
24MHz 0.5µV (-113dBm) 0.11µV (-126dBm) 0.09µV (-128dBm) 56µV 16µV 9µV
28MHz 0.45µV (-114dBm) 0.11µV (-126dBm) 0.1µV (-127dBm) 63µV 14µV 9µV
50MHz 0.35µV (-116dBm) 0.13µV (-125dBm) 0.1µV (-127dBm) 63µV 20µV 13µV
AM sensitivity (28MHz) Preamp1: 0.5µV for 10dBs+n:n at 30% mod depth
FM sensitivity (28MHz) Preamp 1: 0.15µV for 12dB SINAD 3kHz pk deviation
AGC threshold Preamp 1: 1.2µV
100dB above AGC threshold for <1dB audio output increase
AGC attack time: 3-4ms
AGC decay time: approx as specied
Max audio at 1% distortion: 2.3W into 8Ω, 4.0W into 4Ω
Inband intermodulation products: better than -60dB
S-READING INPUT LEVEL USB
(7MHz) PRE OFF PREAMP 1
S1 5µV 1.8µV
S3 8µV 2.8µV
S5 14µV 4.7µV
S7 25µV 8.5µV
S9 50µV 16µV
S9+20 500µV 160µV
S9+40 5mV 1.6mV
FILTER IF BANDWIDTH (SHARP)
-6dB -60dB -80dB
10kHz FM 10.4kHz 13.8kHz 14.8kHz
6kHz AM 6.4kHz 10.4kHz 11.5kHz
2.4kHz USB 2530Hz 3466Hz 3859Hz
500Hz CW 516Hz 669Hz 812Hz
250Hz CW 254Hz 345Hz 545Hz
100Hz CW 108Hz 193Hz 396Hz
50Hz CW 64Hz 135Hz 264Hz
S9+60 50mV 16mV
INTERMODULATION (50kHz tone spacing), 2400Hz bandwidth, 15kHz roof, USB
------PREAMP OFF------ -------PREAMP 1-------- --------PREAMP 2------- 3rd order 2 tone 3rd order 2 tone 3rd order 2 tone
Frequency intercept dynamic range intercept dynamic range intercept dynamic range
1.8MHz +33.5dBm 106dB +26dBm 109dB +16.5dBm 104dB
3.5MHz +39.5dBm 110dB +28dBm 109dB +17dBm 103dB
7MHz +44.5dBm 114dB +32dBm 113dB +19.5dBm 106dB
14MHz +45.5dBm 114dB +32.5dBm 112dB +21.5dBm 106dB
21MHz +45dBm 113dB +31.5dBm 112dB +19dBm 105dB
28MHz +45dBm 113dB +31.5dBm 112dB +18.5dBm 104dB
50MHz +31dBm 105dB +17.5dBm 102dB +12.5dBm 100dB
CLOSE-IN INTERMODULATION ON 7MHz BAND, 500Hz bandwidth, CW, Preamp off
INTERMODULATION LIMITED DYNAMIC RANGE
Spacing 15kHz ROOF 6kHz ROOF 3kHz ROOF 1.2kHz ROOF
1kHz 101dB 101dB 102dB 105dB
2kHz 101dB 102dB 102dB 109dB
3kHz 101dB 103dB 104dB 110dB
4kHz 101dB 104dB 106dB 110dB
5kHz 103dB 106dB 108dB 110dB
7kHz 106dB 108dB 110dB 110dB
10kHz 110dB 111dB 113dB 110dB
20kHz 117dB 115dB 115dB 110dB
30kHz 117dB 116dB 116dB 110dB
50kHz 118dB 117dB 116dB 110dB
RECIPROCAL MIXING TRANSMIT
FREQUENCY DYNAMIC RANGE NOISE 7MHz
OFFSET 500Hz BW 7MHz 100W O/P
1kHz 114dB (-141dBC/Hz) -117dBC/Hz
2kHz 117dB (-144dBC/Hz) -117dBC/Hz
3kHz 118dB (-145dBC/Hz) -122dBC/Hz
5kHz 118dB (-145dBC/Hz) -127dBC/Hz
10kHz 124dB (-151dBC/Hz) -129dBC/Hz
15kHz 126dB (-153dBC/Hz) -137dBC/Hz
20kHz 127dB (-154dBC/Hz) -140dBC/Hz
30kHz 127dB (-154dBC/Hz) -140dBC/Hz
50kHz 128dB (-155dBC/Hz) -140dBC/Hz
100kHz 129dB (-156dBC/Hz) -140dBC/Hz
200kHz 130dB (-157dBC/Hz) -140dBC/Hz
Carrier suppression: >80dB
Sideband suppression: >75dB
Transmitter AF distortion: much less than 1%
Microphone input sensitivity: 1.5mV for full output
FM deviation: 4.4kHz (wide), 2.2kHz (narrow)
SSB-data T/R switch speed: mute-Tx 10-50ms, Tx-mute 5ms,
mute-Rx 35ms, Rx-mute 1ms
TRANSMITTER MEASUREMENTS
CW INTERMODULATION
POWER PRODUCTS
FREQUENCY OUTPUT HARMONICS 3rd order 5th order
1.8MHz 197W -66dB -30dB -42dB
3.5MHz 199W -70dB -34dB -48dB
7MHz 197W -70dB -34dB -48dB
10MHz 200W <-70dB -32dB -47dB
14MHz 198W <-70dB -30dB -46dB
18MHz 200W <-70dB -34dB -46dB
21MHz 202W <-70dB -40dB -47dB
24MHz 202W <-70dB -42dB -46dB
28MHz 202W <-70dB -40dB -48dB
50MHz 195W <-70dB -35dB -51dB
Intermodulation product levels are quoted with respect to PEP.
NOTE: all signal input voltages given as PD across antenna terminal. Unless
stated otherwise, all measurements made on USB with receiver preamp
switched out, 2.4kHz bandwidth sharp lter selected and 15kHz roong lter.
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