OM Power OM4001A User guide

1

MADE IN SLOVAKIA

WWW.OM-POWER.COM

OM Power, s.r.o. 93030 Báč 126,

SLO V A KI A

Co n t a c t : + 4 2 1 905 321 410

e-mail : [e-mail]

OM4001A

SHORTWAVE

POWER AMPLIFIER

2

TABLE OF CONTENTS

1. GENERAL INFORMATION .................................................................... 4

1.1. Introduction ………………………………………………………. 4

1.2. Specification ………………………………………………………. 4

1.2.1. Parameters ………………………………………………. 4

1.2.2. Protection Circuits ………………………………………………. 5

1.2.3. Features ………………………………………………………. 5

1.2.4. The Advantages of OM4001A …………………………………… 5

2. SAFETY INSTRUCTIONS ………………………………………………. 6

3. GENERAL DESCRIPTION ………………………………………………. 7

3.1. HF Compartment …………………………………………………………. 7

3.2. Power Supply …………………………………………………………. 9

3.3. Safety Devices …………………………………………………………. 9

4. INSTALLATION ………………………………………………………. 9

4.1. Grounding ……………….………………………………. 10

4.2. Coaxial Cable ………………………………………………. 10

4.3. Control Cable ………………………………………………. 11

4.4. Cooling ………………………………………………. 11

5. OPERATION ………………………………………………………. 12

5.1. OM4001A Front Panel ……………………………………………. 12

5.2. OM4001A Control ………………………………………………… 13

5.3. Preparing for operation ………………………………………… 20

5.4. Operation mode ……………………………………………………. 26

6. MAINTENANCE ……………………………………………. 30

6.1. Indication of Fault Conditions ………………………………… 30

6.2. Fuse Replacement ……………………………………………. 31

6.3. Tube Replacement ……………………………………………. 32

6.4. Cleaning ………………………………………………. 32

3

7. APPENDIX ………………………………………………………. 32

7.1. Primary AC selection ……………………………………………. 32

7.2. Controlling OM4001A with FLEX Radio Series 6xxx ……………. 34

7.3. OM4001A Remote Control ………………………………..………. 36

7.4. Remote Control using own public IP Address ............................. 40

7.4.1. Changing OM4001A+ connection settings ................................. 40

7.4.2. Setting up in the Remote software ............................................... 41

7.4.3. Remote Control without own IP Address, behind a router .......... 42

7.5. OM4001A firmware upgrade …………………………..………… 43

7.6. Icom connection with OM4001A ……………………………….… 47

7.7. Yaesu plus BPF plus ANT Switch connection with OM4001A … 48

7.8. Control panel connectors pin-out …………………………….…… 49

7.9. Block Diagram of the OM4001A Power Amplifier …………..… 53

7.10. Troubleshooting ………………………………………………………. 54

4

GENERAL INFORMATION

1.1. Introduction

he OM Power model OM4001A is designed for all short wave amateur bands from 1.8 to

29.7 MHz (including WARC bands) and all modes. It is equipped with a two ceramic

tetrodes FU-728F.

1.2. Specification

1.2.1. Parameters

Frequency Coverage Amateur Bands 1.8 – 29.7 MHz including WARC

Power Output 4000+ W in SSB/CW on HF bands

3000 W in RTTY and DIGI modes

Input Power Usually 40 to 60W for full Output Power

Input Impedance 50 Ohm, VSWR < 1.5 : 1

Power Gain 17 dB

Output Impedance 50 Ohm unbalanced

Maximum Output SWR 3 : 1

SWR protection Automatic switching to STBY, when reflected power

is 350W or higher

Intermodulation distortion -32dB below nominal output

Suppression of harmonics < -50 dBc

Tubes 2 x FU-728F Ceramic tetrode

Cooler Centrifugal blower + Axial blower

Power supply switchable 2 x 220 ,230V, 240 V – 50 Hz one or two

phases

Transformers 2 pcs of toroidal transformer 3kVA

Dimensions 485 x 200 x 455mm (width x height x depth)

Weight 46 kg

T

5

1.2.2. Protection Circuits

There are several protection circuits used in the amplifier. They are activated when one
or more parameters exceed defined values or some unwanted condition occurs.

• VSWR too high

• Anode current too high

• Anode voltage error

• Screen current too high

• Screen voltage error

• Grid current too high

• Grid voltage error

• Heating voltage error

• Mistuning of PA

• Temperature too high

• Soft start for fuse protection

• “switch-on blocking “ at opened amplifier

1.2.3. Features

The manufacturer implemented some of the company’s newest development results with
most wanted operating and safety features into this new model:

• High level of protection

• Memory for faults and warnings, easy maintenance

• Automatic set-up anode current (BIAS) – no need to adjust manually after

changing the tube

• Three programmable working modes of the centrifugal blower ( turbine ) + axial blower

• Full QSK with silent relay

• Many operational parameters to display

• Easy transport due to detachable HV transformer

• The smallest and lightest 4000 W Power Amplifier on the market

1.2.4. The Advantages of OM40001A

• Full compatibility with: ICOM, ELECRAFT, KENWOOD, TEN-TEC ORION, YAESU, Icom
transceive protocol using by MicroHAM devices ( CI-V output ), FLEX Radios and
Anan.

• RF sensitive Band and Frequency switching, for use with radios which do not
have CAT. We recommend using CAT and BAND DATA information
due to the much faster band changing whenever possible.

• Automatic switching between bands. Automatic tuning within the band according to segments.

• Automatic switching of Band Pass Filter – BAND DATA output compatible with YAESU radios

(BCD code).

• Automatic switching of Antenna switches. The maximum number of antennas is 10, controlled
by BCD output code.

• Remote control via available PC Application. http://www.om-power.com/download/HF

PA_Manager_

6

2. SAFETY INSTRUCTIONS

DANGEROUS HIGH VOLTAGE INSIDE!

The power amplifier is using high voltage up to 3300 V DC , which is very dangerous for
human life! Read next safety instructions carefully first, before you will start to install
and operate power amplifier! NEVER VIOLATE THE FOLLOWING SAFETY RULES!

NEVER ALLOW CHILDREN to play around PA or to touch power amplifier or connected
cables in working condition, or to push anything into the case holes!

Never turn the amplifier on without the upper lid in place. DO NOT ATTEMPT TO SHORT
OR BYPASS safety switch under upper lid!

The OM4001A amplifier should not be used in a WET or HUMID environment or be
exposed to RAINFALL!

Do not turn the amplifier ON without having connected the ANTENNA or properly rated
DUMMY LOAD! A hazardous HF voltage may build up on the antenna connector after
turning the amplifier on with no antenna or dummy load connected!

Before removing the upper lid of the amplifier make sure that power supply has been
disconnected AT LEAST 10 minutes allowing for the electrolytic capacitors to discharge
fully. Disconnect power cord from the outlet!

Any work inside the PA (internal fuses replacement, tube replacement, etc.) should be
carried out only by a professionally qualified person!

7

CAUTION

The amplifier must be installed in such a way that free flow of hot air from the tube is
allowed. The amplifier must not be installed in a constrained surrounding (i.e. tight
shelves etc.). During extended operation the tube ventilation grid can reach high
temperature. Do not touch it!

The amplifier must be properly grounded during operation.

During operation the amplifier must be installed in such a way that the rear side remains
accessible.

The amplifier is an A category product. In a household it can influence other electric
appliances. In such cases the user is to take proper actions to mitigate this disturbance.

Read this manual carefully. Fallow all of instructions during installation and operation to
avoid damage to the amplifier not covered by manufacturer´s warranty! Do not attempt
to perform any change of hardware or software!

3. GENERAL DESCRIPTION

3.1. HF Compartment

his amplifier is using a par of ceramic tetrode FU-728F in a grounded-cathode circuit
(input into control grids). The OM4001A amplifier achieves excellent linearity by the
voltage stabilization of the control grid bias and the screen voltage. The power input is fed

to the control grids, using a broadband input circuit with an input impedance of 50 Ohms.
This adaptable input circuitry ensures a good input SWR (better than 1.5 : 1) on all amateur
bands.

T

8

The output of the amplifier is a Pi-L circuit. The variable capacitors for TUNE and LOAD are
seperate. This enables the amplifier to be tuned exactly and makes it possible to easily return to
the previously set positions after band changes.

Top view on the opened OM4001A

Tetrode FU728F Blower Switch-ON Board

Output Pi-L Circuit Tuning Capacitor Front Subpanel Power Supply Board

9

3.2. Power Supply

This Power amplifier uses two 3 KVA toroidal transformer. A soft start is provided using relays
and resistors (placed on the switch-ON board). The high voltage is made by combining 8 x 420

V (total 3360V) @ 2.5A . Each has its own rectifier and filter. In the high voltage circuit, safety

resistors are employed to protect the amplifier against overload (placed on the power supply
board).

The separate screen grid supply is regulated and stabilized with MOSFET circuits and delivers
abt. 350V DC at 200mA. Control grid voltage is also stabilized (-120V DC). Change of
stabilized first grid voltage is controlled by the software (EBS for example).

The transformer primary is Tap adjustable for 220 , 230 or 240V AC.
The factory setting is 230 VAC .

If the AC voltage in your network is 220 or 240 Volts, you need to set the correct
transformer tap before first starting the PA. See part 7.1. for more information. Other primary
voltage is possible on request (for example 200V 50/60 Hz for Japan).

3.3. Safety Devices

Control and monitoring circuits ensure control and safety during malfunctions of the PA. These
are placed on the Control board, which is located on the chassis subpanel.

One of the important safety elements is a
mechanical switch for AC blocking an
opened amplifier.

4. INSTALLATION

Read this chapter carefully prior to starting installation. Before unpacking inspect
shipping carton for any damage. Keep all of packing parts for possible future
shipment. Check unpacked power amplifier. If you find any damage, contact your

dealer immediately to keep full warranty.

10

4.1. Grounding

The amplifier has to be grounded properly! Connect the screw on the rear panel
of the amplifier to your local grounding system with a copper cable; use a cross­section of 4 mm2 at least.

Connect your transceiver to the same grounding system of your shack carefully! Use minimum
length cables and make certain that the connections are both physically and electrically sound.
With poor grounding, you may risk damaging your equipment, have problems with TVI/BCI or
possible distortion of your transmitted signal.

4.2. Coaxial Cable

The output of the transceiver is to be connected to the input of the amplifier via RG58 or similar
50 Ohm cable. For the connection between the power amplifier and the antenna, RG213 or
similar coaxial cable suited for high power is recommended. SO-239 sockets with Teflon
insulation are used for the HF INPUT and OUTPUT connectors.

Rier view of the amplifier OM4001A

Mains Plugs Fuses HF Output

Grounding point Blower Control HF Input

11

4.3. Control Cable

Control cable maintains TX / RX switching of the PA (TX GND). The cable is shielded. On the
side of the power amplifier a CINCH-socket is used. On the side of your transceiver you have to
use a socket suitable for this transceiver. During transmitting the middle pin is connected to the
ground. The relays of the OM4001A have to be switched earlier than HF is applied (cold
switching). Modern transceivers they have a time delay between PTT switching and power
output.

If you are using an older transceiver or transmitters without time delay, we
recommend to connect the PA in such a way that the transmit/receive switch (foot

switch for example) is connected with the KEY IN socket of the amplifier. The KEY
OUT socket is to be connected with the PTT socket at the transceiver. If there is
possible to adjust TX delay in your TCVR, set the delay to 15ms, please.

The amplifier is equipped with safety devices, which ensure that the output relay is not switched
under power mistakenly (hot switching).

KEY IN RCA Phono - Input signal PTT switching voltage / current - 5V /2mA)
KEY OUT RCA Phono - Output signal PTT (maximum switching of 30V / 50mA)

See section 7.9. for Control and ANT/BPF connector PIN-OUT.

Be sure that your power system is correctly wired and properly rated! To use an
adequately sized and connected grounding system is also very important!

4.4. Cooling

The amplifier must be installed in such a way that free flow of hot air from the

tube is allowed. Do not obstruct air intake and exhaust areas of the PA.

The centrifugal blower provides the necessary cooling of the amplifier, even during long
contests. The blower is activated by switching the PA on and it is turned off when cooling is
finished (approx. 1-5 min after switching off the PA depending on the temperature of the tube).
Blower working mode is programmable (3 modes). See page 20-21 for more details.

12

5. OPERATION

Before switching PA on, make sure that amplifier is grounded, antenna or
dummy load is connected, and line cord is plugged into the outlet. Be sure you

have selected the proper AC input TAP (Sect 7.1)

Do not turn PA on for at least 2 hours after unpacking and located in its operating

location. Especially when amplifier is moved from a cold place to a warm one as

condensation may develop. This condition could result in damage to the high
voltage circuits.

We do not recommend changing antennas during a transmission. (Hot switching)

When you decide to have a short operating break, We recommend placing the
amplifier to the standby mode rather than switch it off.

5.1. OM4001A Front Panel

Front panel of the OM4001A is almost empty…Containing only the touch TFT display plus two
control switches.

ON - Main Switch. After turning ON, a small 12V APU for logic, protection circuits and the

display will be activated. High voltage and RF circuits are still OFF.

13

OPR/STBY - Short press for switching betwen STBY and OPERATION mode.
ON/OFF - Long press (1 sec.) for switching the PA ON (tube heating first), 2 seconds for

PA OFF. Always use the ON/OFF button as this allows for a predetermined (software
controlled) time to cool down the tube and inside the PA compartment.

5.2. OM4001A control

Turn ON the green Main Power switch and the home screen will lights up. Initial control touch
buttons are visible on the bottom line.

Remember that the home touch screen is active for some information and control settings ,
while the PA is still OFF!

BAND

Touch the left side of BAND button to go down, touch the right site to go up. The band
information is displayed above the button.

ANTENNA

Transmitting antenna choice. Functional ONLY when the antenna switch is programmed and
antennas are defined (see page 17). This antenna feature allows switching between antennas
authorized for the current band. An external antenna switch is controlled by BCD code at the
ANT/BPF output (see Section 7.9).

INFO

Information display shows basic information about the PA: serial number, software version, time
ON, tube serial number and nominal Main voltage.

14

The information screen also
provides an overview of the last
20 warnings and faults:

Press FAULTS.

Press EXIT to go back to the home
screen.

Now press SETTINGS. This
display shows various menu
settings for CAT, NO CAT,
ANTENNA, DISPLAY, EBS,
CLEAR user settings for one or all
bands, BLOWER mode and other
INFO.

15

Screen shows settings possibilities
for CAT, ANTENNA, DISPLAY,
NETWORK SETTING, EBS,
BLOWER and other INFO.

Scroll to CAT SETTINGS (up or
down) and

press SET.

Scroll to your TCVR family (up or
down)

select appropriate bit rate (left or
right)

then press SET.

Or select NO CAT and press SET.

We recommend using the CAT connection whenever possible because, in such a case, the
OM4001A has permanent information about the transmit frequency and is immediately ready for
transmitting.

With a setting of NO CAT the OM4001A detects transmit frequency from the input signal. With
the input signal frequency changing the PA automatically reacts and tunes itself to optimal
output parameters.. If NO CAT is used, we recommend using BAND DATA (BCD) information
for much faster band changing.

If you choose YAESU or ICOM
NEW, after SET pressing you will
go to deeper level which allows
you to select specific type of
TCVR.ee the following picture for

ICOM NEW selection, for example.

16

You selected IC7800 addr.6AH
and 19200 Bd. Press SET to write
to the memory, then press EXIT to
go back to the SETTINGS
possibilities.

“SET OTHER ADDRESS” means
that you must add here a new type
of ICOM TCVR which is not
defined in the table (its address
plus bitrate in Bd) to allow
communications with it.

Press ANTENNA SETTINGS. First
select ANTENNA SWITCH (No
switch, Standard). Use left or right
arrows. If you select some switch,
10 ports for different antennas
displays. Generally all of antennas
are allowed in every band (green
squares). To disable some square
select port (up/down), touch SET
for antenna name and then select
band (left/right). Press SET.

Four types of antennas for four
different bands were disabled.

Black square means disabled
combination.

Press EXIT to go back to
SETTINGS menu

BCD code (4 bits) is used for automatic antenna and BPF switching (see Antenna/BPF

connector on the Control panel (rear side of the PA). See section 7.9 for Control and
ANT/BPF connectors pin-out.

17

Next SETTINGS position is for
display parameters. First choose the
background color. Scroll on it and
choose the color (left/right).

Press SAVE twice, then scroll to

OWN CALL.

Press SET for your callsign edit. The
keyboard displays.

Type your callsign and press ENT.

Use next lines and set brightness and
sound volume (use up/down and
left/right). Confirm with SAVE.

18

Press NETWORK SETTING and
then press ENTER.

Here the user has the option to set
IP Address, Network mask,
Default gateway, Port number.

User can enable or disable IP
parameter setting via LAN
connection.

Next lines are for EBS (Electronic
Bias Setting) ON/OFF and for
EBS level selection.

We recommend EBS ON. See
next comment for more details.

19

Electronic Bias Settings (EBS) is a significant feature of this power amplifier. It automatically
allows lower plate current after pressing the PTT, regardless of whether operating CW or SSB
mode, when no RF signal is present at the input. At the moment an RF signal is applied, the
bias will automatically change to its working value.

EBS level means level of the Input power where EBS starts working. Default EBS value is 0.1
W. We recommend turning EBS ON. A significant feature of using EBS is PA operating
temperature reduction.

NOTE: If you are not using compression in your TCVR,or you are not speaking loud enough,
some syllables can be cut off. In such a case you should turn OFF the EBS.

The next two settings allow
deletion of the manual user
settings of the amplifier tunings
for a single band or for all
bands.

Settings in all segments will
return to the factory default
values (for 50 Ohms).

In the next line you can define
working mode of the blower. In
the first mode speed depends
on the PA temperature (TEMP),
In PTT mode the speed
increases to maximum, and the
ALLWAYS mode means
maximum speed all the time
during PA operation
(recommended for DIGI
modes).

Press SAVE to write the mode to the memory.

20

The INFO settings allows
viewing all of the previous PA
INFORMATION screen plus the
addition of one more touch key
to enter the UPGRADE mode.

UPGRADE touch button
should ONLY be used if the
EEPROM or firmware files (or
both) will be upgraded. In such
a case ask the dealer or
manufacturer for the exact
procedure.

5.3. Preparing for operation

In STBY the amplifier is in bypass-mode and your transceiver is directly

connected to the antenna. Maximum allowed power in bypass mode is 200 Watts!

The bypass RF power is displayed if PA is in standby mode.

To turn PA ON press ON/OFF button on the front panel (black one) and hold it abt. 1 second.
PA will start tube heating. It will take 180 seconds. Turning PA ON is possible ONLY from the
home screen! If you have other display active, press EXIT more times to go back to the home
screen. (These same functions are also available on the OM Power Remote Control PC
Application)

21

The “Tube Heating Timer” is
visible on the display. Wait until
the required 180 seconds is
complete before placing the
amplifier in OPERATE Mode.

After heating is completed, the
PA will light the STBY mode
indicator and this Main display
will appear.

NOTE: If CAT or ANTENNA
settings are populated the
associated windows will reflect
these settings.

Depending on CAT settings you would have two possible situations illustrated. If NO CAT was
saved, the above display will be visible. To manually set band and segment for transmitting,
use BAND and SEGMENT buttons. In this mode exact frequency will be read from RF input and
PA will set up on it automatically.

COM. LOST appears if CAT was defined but TCVR is not connected with the PA (CAT cable).
See the following pictures.

FREQ button has two functions.
It allows displaying the working
frequency or active band
segment.

NOTE: If CAT is used the
working frequency will be read
directly from the TCVR.

Use ANTENNA (left/right) to
select one of the preprogramed
antenna for that band.

22

The Menu display allows the user to
go deeper into the SETTINGS mode,
MEASuring mode or SERVICE mode.

Press SETTING button.

We are in the settings mode again, but
with a new submenu called INFO.

Scroll to INFO and press SHOW.

A new button is visible – SET Umain.
Press it.

23

Type in the actual setting of the primary
voltage tap and press ENT.

Press EXIT twice to go back to the
Menu display.

This is the actual physical setting of the primary voltage tap. It is just information for the

processor, which protects the permitted limits ( up or down) for a given value of the

primary voltage (protection circuit).

Pressing MEAS displays this screen.
Instantaneous values of the basic
amplifier parameters are displayed.

NOTE: You can FREEZE the screen
and/or allow constant monitoring.

Three different bar graphs can be
defined using BARG1, BARG2 or
BARG3 buttons.

Press BARG1.

Green graph may show one of the user
selectable 8 monitored parameters.
Select the wanted parameter from the
list at the bottom of the screen and
press SAVE.

NOTE: Follow these steps to populate
BARG2 and BARG3 as desired.

24

Press EXIT to go back to the Menu
display, then press SERVICE.

Now we are in the SERVICE settings
mode.

Scroll to selected line and press
SHOW or SET (depending on the
line).

We selected last 20 FAULTS to show.

Press EXIT

Go to SET EBS1 AUTO and press
SET.

PA will automatically set 20mA on the
front and back tube separately. When
finished successfully, you will see
SET EBS1 AUTO OK on the screen

25

You can try to do this manually, too.

Scroll to SET EBS1 MANUAL and
press SET.

Use up/down buttons to set 20mA or
as close as possible value and press
SAVE.

Similar ways EBS2 can be preprogrammed (300mA by AUTO set).

Or another value of EBS2 by MANUAL Set.

Scroll to CALIBRATION Ip, Is and
press SET. Calibration will be done
automatically.

Scroll to SWR PROTECT and press

SET.

This feature allows user to switch
OFF the SWR This feature allows
the user to switch OFF the SWR
protection.

We recommend to set it ON (SWR
protection circuit will stay active, max. allowed SWR is 3:1). If OFF is selected, higher SWR is
allowed, but reflected power is measured. If it exceeds 350W, transmit will be blocked.

Press EXIT.

26

5.4. Operation mode

Before switching to operation mode, check all connections between PA and
TCVR.

We are now back in the Main
display, bar graphs defined,

antennas preprogrammed, CAT was
set. We are ready to go to the
operation mode.

Press the black STBY/OPER button
on the front panel.

We are now in OPERATE mode.

Note the light indicator on the touch
Screen has changed to OPERATE .

Press MENU.

Now try to press PTT (foot switch for
example).

We are now in TRANSMIT mode
(without RF).

Note the new TRANSMIT light
indicator on the touch screen.

We also have a new M-TUNE button
here.

27

M-TUNE means entry into the manual tuning mode. It allows fine tuning of the PA, especially in
cases where the antenna impedance is different from real 50 Ohms. For proper adjustment we
need to show Screen current (at least). By Pressing M-TUNE. A new screen is visible and
TUNE and LOAD adjustment sliders appear.

M-TUNE Adjustment process: Move TUNE left or right until maximum FWD power is reached.
Then move LOAD carefully so that Ig2 Screen (I Screen on the display) current will not be
higher than 40mA. Repeat this process until the tuning process is optimal at the desired power
level.

The result of the tuning process is optimal when the PA is tuned for maximum forward power
and Ig2 current stays in the 0 to +40mA range. At that time maximum efficiency and optimal
linearity are achieved. This applies to each power application. It is not necessary to retune the
PA, if we decrease the output power. The PA stays in linear mode with slightly lower efficiency.
If we increase the output power, retuning is necessary only if Ig2 exceeds +60mA.

Press SAVE for writing values to
the memory and press EXIT.

NOTE: Repeat M-TUNE
adjustment process for other
segments / bands as required.

Below is an example of an M-TUNE situation. First we will check driving power from the
transceiver. Stay in STBY mode, press PTT and apply RF power.

Measured driving power is 30
Watts.

Now switch to OPER, press
PTT and apply RF from TCVR.
See the following picture.

28

Output power is 4113W, reflected
power about 1W and screen
current is about +50 mA.

NOTE: If your antenna impedance
is different than real 50 Ohms
then can be necessary to start the
M-TUNE procedure to optimize
the PA tuning.

Press MENU, M-TUNE) and make
the manual adjustment.

This is the result after manual
adjustment process. Screen
current is now abt. +30 mA.

These parameters were SAVED.

NOTE: The OM4001A is factory adjusted to a maximum output power of 4000W into a 50 Ohm
load. A unique Tuning table, with TUNE and LOAD values for every band, is supplied with
each PA.

When the antenna impedance has greater variance from 50 Ohms, it may be the case that the
PA cannot deliver the full power 4000W, or some of the protection circuits may be automatically
activated. In such cases we recommend doing a manual tuning. (M-TUNE)

The best indication of proper PA tuning is the Screen Current. In the properly tuned PA this
should be within 0 to + 40mA (at full output power).

M-TUNE Tuning procedure:

• Press M-TUNE button. If CAT is active, the TCVR will automatically tune itself to the
middle frequency of the segment. If NO CAT, you must tune the TCVR manually to the
segment center frequency. If NO CAT but using BCD, the band will be changed but the
segment will only be set after keying. (Set CW or RTTY mode in the TCVR.)

NOTE: Set input power to about 25 watts to begin.

29

• Press PTT, check the Ig2 (I Screen on the display). If it is ok (bellow +40mA ),
gradually increase the input power until the PA reaches about 70% of its maximum
output power.

• Using the TUNE buttons, adjust for maximum FORWARD POWER while monitoring the
Screen current.

• When the Screen current exceeds +60mA , adjust the LOAD button to decrease Screen
current to about 0 mA.

• Increase the PA input power until you reach the desired maximum output power. Keep
watching the Screen current. If the Screen current exceeds +60mA decrease it by using
the LOAD button.

• Repeat using the TUNE buttons to reach desired maximum FORWARD POWER and
check Screen current.

• If the Screen current is lower than 0 mA (negative value), change it by pressing the
LOAD button until 0 mA is set and check again for maximum output power. Do not start
with very low input power, set abt. 50% before beginning M-tune process.

• If you reached the desired maximum output power, and the PA Screen current is inside
0 / +40mA , then press the SAVE button.

Notice 1: If the tuning process takes more than 1 minute, allow for a short break to prevent
temperature overloading of the PA.

Notice 2: If you use the PA with the output power adjusted lower than the maximum settings ,
Screen current can take negative values. There is no need to readjust the PA, it is still working
in the linear mode.

We can now see a new small
yellow USER window in the touch
screen display. USER means that
we used the M-TUNE feature to
optimize the PA adjustment.

If you want to go back to the
default factory settings, use
CLEAR USER SETTINGS in the
MENU settings (page 19) for one

band or all bands.

If the amplifier demonstrates any malfunctions during tuning or it does not behave in
accordance witch the M-TUNE procedure, interrupt the tuning procedure immediately
and check the amplifier! Be sure there are not any mistakes in choosing antennas, bands
or segments! Insure that VSWR is not higher than 3:1 and input power is LOW!

30

6. MAINTENANCE

6.1. Indication of Fault Conditions

If a fault condition appears during the operation of the amplifier, the safety circuits of OM4001A
will react immediately. There are several types of warning or fault messages that may appear on
the display when any of the protection circuits are activated. The OM4001A power amplifier
provides the following protection:

Power Out is too high
Refl. power too high
Power In is too high
Low output power (tune)
Plate current too high
Grid current is high
Screen current error
Heating voltage error
HARD FAULT
Plate voltage error
Grid voltage is low
Screen voltage error
SWR is too high
Amplifier is too hot

Most of the safety circuits are preset for two levels of activation. The first level is a

warning level. In such a case a warning message appears on the display but the power

amplifier will stay in normal operation. See the table above for warning and fault

conditions.

When a fault condition occurs during the tuning or operation of the amplifier, the safety

circuits will block transmitting. The amplifier stays in OPER mode. After approx. 1 sec

the control circuits will automatically switch the amplifier back to the transmitting mode.
If the problem persists, the safety circuit will react again and the appropriate fault

message will appear on the PA status screen.

If the fault repeats 3 times during a 10 seconds interval, the safety circuits will
turn the amplifier to STBY mode. Cancelling a fault condition takes a short press
of the STBY/OPER button. The PA will stay in STBY mode.

NOTE: All the warning and fault messages are stored in the onboard memory. You can display

particular warning messages and particular error messages. They are stored up to 20 at a time
to the memory. You can view them on the menu display. If the error memory is full, every new
message will delete the oldest one in the stack. It means that every only the last 20 messages
are visible on the display.

31

This is an example from a
previous attempt at transmitting
when the antenna was
disconnected from the PA .

Reflected power was higher
than 350W and a warning
message “Reflected power too
high” appeared.

If you touch the yellow “last
events” box on the PA touch
screen it will display the warning
details.

In the case of some hardware
failure or if your power amplifier
is not working properly, please
contact the manufacturer or your
local dealer.

Never try to change or move any part inside the amplifier except the tube or
fuses. Substitution of parts may void intrinsic safety!

Manufacturer’s contacts: OM POWER, s.r.o.
930 30 Báč 126
SLOVAKIA

Email: [e-mail]

6.2. Fuse Replacement

The user is allowed to change mains fuses (6.3 x 32mm), accessible from the rear panel, only.
In the case of fuse (fuses) interruption inside the power amplifier, exchange can be carried out
only by professionally qualified persons! Internal fuses are located mainly on the SWITCH­on board (next to the HV transformer).

32

One special fuse, filled with sand, is used in the model
OM40001A. In the case of an accidental discharges or short
within the tube this fuse (4 Amps fast, filled with sand) saves
the HV supply circuits.

Fuse F 4A

6.3. Tube Replacement

In the case of a damaged vacuum tube , contact the manufacturer or your dealer for ordering a
new one. We will provide instructuions for replacing the tube. Replacement should be done by
a professionally qualified person! After tube replacement the automatic BIAS adjustment
procedure must be done.

6.4. Cleaning

To prevent damage to the amplifier surface and plastic components, do not use aggressive
chemicals for cleaning. Do not open the amplifier for cleaning. Outer surface cleaning may be
safely accomplished by using a piece of soft cotton cloth moistured with clean water or window
cleaner.

7. APPENDIX

7.1. Primary AC voltage selection

Primary section of the HV transformer is switchable for three values of AC voltage (220, 230,
240V) Factory settings is 230VAC. Before first starting the PA we recommend checking that the
correct value is selected according to the AC voltage in your network.

33

Side view on the opened OM4001A

HV supply board AC Selector SW ON board

HV Transformers

Remove the upper lid first. On the right side of the PA, there are two PCBs mounted. On the
right upper side is Switch ON board where AC selector is located.

There are AC selector for each
transformer. The blue wire – one side
of primary winding is conected to N
pole. Wire marked with proper voltage
connect to L pole.

AC voltage is marked at every black
terminals.

34

AC selector range can be changed according to the specific conditions in individual

countries. Default settings is 220, 230, 240V / 50Hz for EU market and 230, 240, 250v /
60Hz for USA market. If you need different settings in the range of 200 – 260V, this

should be specified in the order!

Manufacturer reserves the right to make future changes in the way of connecting the

transformer to the board. Allways mark the position of the terminals before
disconnecting the transformer.

7.2. Controlling the OM4001A with Flex Radios Series 6xxx

There are two possible methods to connect the Flex Radio series 6xxx to the OM4001A:

• Using the SmartSDR CAT program

• Using the USB connector at Flex 6xxx

Flex Radio 6xxx series connection using SmartSDR CAT

Choose the control port in the SmartSDR CAT window that you will use to control the power
amplifier. It must be an existing serial port – a hardware COM port in your PC or an USB to
serial port adapter. Connect the chosen COM port and the transceiver port ( TCVR DB9 )to the
OM Power amplifier with a null modem serial cable (both ends of the cable have a female DB-9
connector and pins 2 and 3 are crossed).

You must assign this serial port to the TX slice that is associated with the Flex 6XXX.
otherwise the amplifier will not set on the proper frequency.

35

In the CAT SETTINGS menu select

FLEXRADIO, baud rate 9600 and press SET.

NOTE: If you have already configured other

programs to communicate with the Flex
6XXX using a different baud rate then set the
same baud rate for the Amplifier CAT setting.

Flex Radio 6xxx series connection using USB output

Connect from the Flex USB port directly to the TCVR port on the OM4001A using an USB –
FTDI serial port adapter and a null modem serial cable (both ends of the cable have a female
DB-9 connectors (pins 2 and 3 are crossed).

NOTE: A USB adapter equipped with a genuine FTDI chip set is a must. Knock off FTDI chip
sets do not work properly.

Now connect the DB9 end of the null modem cable/FTDI adapter to the TCVR port on the
OM4001A.

Activate Smart SDR and from the Flex SSDR main screen choose Settings then USB Cables

Now connect the USB-FTDI adapter to a USB port on the Flex radio. A new line showing the
connected USB adapter will appear.

36

Double click on the new usb adapter line to open the configuration window for this COM port .

Set all parameters in the configuration window according to the picture below.

Check that ENABLED is selected in both associated USB windows.

Close both windows. The OM4001A will now follow the Band and Frequency changes on the
Flex 6XXX.

7.3. OM4001A Remote Control

The OM Power team has developed special software which allows controlling the PA OM4001A
remotely. Download it from the official OM Power website http://www.om­power.com/downloads. The software allows the following controls:

• Switch the PA ON and OFF

• Switch between STBY and OPERATE

• Switch between preprogrammed antennas

• Read and reset the last 20 warnings and fault messages

• Manual fine tuning of the PA Tune and Load

• To check most operating parameters of the PA

• Selection of different screens for the PC display

• Antenna retuning if parameters changed

Have a look on the next pictures and follow instructions to setup remote control properly.

37

Connection setting:

Set up TCP/IP address and port:

Connect / disconnect to OM4001A:

38

View last 20 PA faults:

Anennas Settings:

Screen selections:

Minimal view:

NOTE: To return to the normal view from the minimal view just right click with your mouse

39

Normal view:

Advanced view:

Fine tune screen: It is possible to retune the PA TUNE and LOAD remotely (See page 31).

40

7.4. Remote Control using own public IP address:

7.4.1 Changing OM4001A connection settings

Connect the LAN connector on the
OM4001A to your local Internet with
ethernet cable.

Open up a WEB browser and enter the
OM4001A current IP address (default is

192.168.1.222).

An authentication window will show up. Leave the fields empty and click OK.

Open the Network menu and change the IP address, Subnet mask, Default Gateway and DNS
Server settings to the ones given by the internet provider. When done, click OK.

41

If necessary it is also possible to change the OM4001A local Port number. Make any changes
as required in the Connection menu. When finished, click OK.

When completely finished, click Apply Settings in the main Menu.

7.4.2 Setting up in the Remote software

In the Remote Control software
open the Manager Settings and
enter the IP Address and Port
number that you set in point 7.5.1.

Press enter, when done. Now you
are ready to work with the
OM4001A over the internet.

42

7.4.3 Remote Control without own IP Address, behind a router

If you need to change the OM4001A connection settings for some reason, use point 7.5.1
above.

Change router´s settings

Open up a WEB browser and enter
the routers´s internal IP Address (
usually 192.168.1.1)

An authentication window WILL
APPEAR. You need to enter the
routers login and password. Usualy a

router´s default login is “admin” or

“administrator” and default password
“admin” or an empty field.

Open Firewall Settings (depends on router software, can be called Forwarding, Port Forwarding, or
something similar). As Server IP enter the OM4001A IP Address, 192.168.1.222 if you haven't changed
it, or the one you changed to in point 7.5.1. Private port should be 10001 in default, or the one you
changed to in point 7.5.1. Some routers don't have separate Public Port settings. Enter an available port
number (usually the default 10001 is free and usable). Check the Enable box too. When done, click OK
(or Save).

43

Open your Basic Router Setup (or WAN Settings or similar, depending on router) and note the WAN IP
Address value.

In the Remote Control software,
open the Manager Settings. Enter
the IP Address and Port number
you set up previously in your
router. IP Address is the WAN IP
Address from the basic setup page
and the Port number is the Port (or
Public Port if separate) from the
port forwarding page.

Now you are ready to work with OM4001A over the internet.

7.5. OM4001A firmware upgrade

Download the firmware upgrade software and latest firmware file for the OM4001A from the
official OM Power website http://www.om-power.com/downloads. Store it to OM4001A folder
created on your PC.

NOTE: Use a serial null modem cable and connect the TCVR port on the OM4001A rear panel
with a COM port on the PC.

44

Open folder OM4001A on your
PC, find the MX460L.exe file and
run it.

Select SETTINGS and choose the
COM port you want to use. Baud
rate should be 115200. Close the
window.

Select the Firmware tab and click
on the LOAD BIN button.

Choose OM4001A Vxxx.bin file in
the OM4001A folder.

45

Switch ON the power amplifier using the
front panel green ON switch.

Press SETTINGS to enter the
SETTINGS Menu.

Choose INFO and press SHOW.

Press UPGRADE to start the Amplifier
upgrade process..

When you see this screen on the PA, go
to the PC and the PIC Loader software
and press button the SEND TO LINE
button.

46

Press the SEND TO LINE button.

Press LOAD on the OM4001A to start
loading.

You can see the loading progress on
the bar graph

You will see this screen after the
firmware was successfully loaded

Usually, it takes about 30 seconds but
sometimes it might take a little bit
longer.

NOTE: Do not take any action until this screen disappears!

At the end you will return to the main screen of OM4001A. Switch PA OFF, disconnect the
TCVR serial cable and you are ready to use the OM4001A with the new firmware.

47

7.6. ICOM connection with OM4001A

AC 1

GND

OUT

LAN

COM port RS 232

PC

to ANT

ANT2 ANT1

SEND

REMOTE

TRX ICOM

REAR VIEW

OM4001A

PC

TCVR CI-V

IN

KEY

ANT & BPF

CONTROL

INPUT

OUTPUT

F2

F1

AC 2

48

7.7. Yaesu plus BPF plus ANT Switch connection with OM4001A

AC 1

OM6BPF

BCD decoder

GND

OUT

LAN

REAR VIEW

OM4001A

PC

TCVR CI-V

IN

KEY

ANT & BPF

CONTROL

INPUT

OUTPUT

F2

F1

AC 2

ANT switch

Bandpass filter

OUTPUTINPUT

TX GNDBAND DATA

CAT

COM port RS 232

PC

ANT

ANT2 ANT1

SEND

RS 232

FT1000MP / FT9000

49

7.8. Control panel (rear side) connectors pin-out

TCVR connector DB 9 male

RS232 connection with TCVR. For CAT communication connect pin 2
RX-D, pin 3 TX-D and pin 5 GROUND

CI-V connector Use CI-V connection for communication with ICOM type

transceiver. Signal CI-V is connected to the Tip.

50

PC connector DB 9 female

RS232 connection to the computer. For CAT communication connect pin
2 TX-D, pin 3 RX-D and pin 5 GROUND

KEY IN – RCA connector

Input signal PTT switching voltage / current 5V /2mA)

KEY OUT – RCA connector

Output signal PTT (maximum switching of 30V / 50mA)

LAN connector

Use for connection to the LAN or WAN network.

51

CONTROL connector D-sub 15 female

Pin 1 - GROUND
Pin 2 - KEY OUT - ouput signal PTT ( maximum switching of 30V / 50mA
Pin 3 - KEY IN - input signal PTT – switching voltage / current 5V / 2mA
Pin 4 - CI-V - CI-V input for Icom CAT. The same as CI-V jack connector
Pin 5 - BAND data A input - input BCD Yaesu compatibile code from TCVR - bit 0
Pin 6 - BAND data B input - input BCD Yaesu compatibile code from TCVR - bit 1
Pin 7 - BAND data C input - input BCD Yaesu compatibile code from TCVR - bit 2
Pin 8 - BAND data D input - input BCD Yaesu compatibile code from TCVR - bit 3
Pin 9 - GROUND
Pin 10 - CI-V SW - connect to Ground if you use CI-V input on pin 4. Not used for CI-V with Jack
3,5mm
Pin 11 - IC band data - Icom Band data input. Band data information from ICOM TCVR
Pin 12 - INHIBIT - Inhibit output for TCVR. +12V/2mA inhibit transmit, 0 V if transmit is allowed
Pin 13 - No connect
Pin 14 - No connect
Pin 15 - No connect

ANT / BPF Connector - D-sub 15 male

Pin 1 - ANT data D - output BCD code - bit 3 for antenna switching
Pin 2 - ANT data C - output BCD code - bit 2 for antenna switching
Pin 3 - ANT data B -- output BCD code - bit 1 for antenna switching
Pin 4 - ANT data A - output BCD code - bit 0 for antenna switching
Pin 5 - Not connected
Pin 6 - GND
Pin 7 - GND

Pin 8 - +12V /100mA - output supply 12V maximum 100mA for antenna BCD decoder

52

Pin 9 - BAND data A - output BCD Yaesu BAND data compatibile code.Use for automatic bandpass filter
OM6BPF

Pin 10 - BAND data B - output BCD Yaesu BAND data compatibile code.Use for automatic bandpass filter
OM6BPF
Pin 11 - BAND data C - output BCD Yaesu BAND data compatibile code.Use for automatic bandpass filter
OM6BP
Pin 12 - BAND data D - output BCD Yaesu BAND data compatibile code.Use for automatic bandpass filter
OM6BPF
Pin 13 - Not connected
Pin 14 - GND
Pin 15 - 12V /100mA – the same as pin 8

OM2000A+ can address up to 10 antenna port, see antenna BCD code table below

D C B A Logic value

Antenna port

0 0 0 0 0

UNDEFINED

0 0 0 1 1

ANT 1

0 0 1 0 2

ANT 2

0 0 1 1 3

ANT 3

0 1 0 0 4

ANT 4

0 1 0 1 5

ANT 5

0 1 1 0 6

ANT 6

0 1 1 1 7

ANT 7

1 0 0 0 8

ANT 8

1 0 0 1 9

ANT 9

1 0 1 0 A

ANT 10

1 0 1 1 B

UNDEFINED

1 1 0 0 C

UNDEFINED

1 1 0 1 D

UNDEFINED

1 1 1 0 E

UNDEFINED

1 1 1 1 F

UNDEFINED

53

7.9. Block Diagram of the OM40001 Power Amplifier

J1

J11

Rezerva

Supply

PWR

Output

Box IO

HV supplySW ONInput

Temp

J11

J2

board

Heating control

HV supplySW ON

K2

Bias

Supply

J2

J8

J7

J6

M3

M2

M1

J9

J8

J7

J6

J1

J3

J4

J2

J5

I/O BOX

ANT+BPF

CONTROL

PC

LAN

CI-V

TCVR

333

3

3

3

J5

CONTROL BOARD

DISPLAY

J4J3J2

J14

J10

J9

KEY IN

KEY OUT

LOADTUNE

J12

Ext.bl.

K2

K3Kl 8

Kl 7

K1

Kl 3

Kl 4

Kl 2

Kl 1

K1

J5

J8

TR2

TR1

AC24V

AC2

AC1

J9

J6 J1

Cover SW

OM 4001A Block diagram

Fuse

Blower

SW ON BOARD

HV SUPPLY

OUTPUT

AC 2

AC 1

INPUT

PWR METER

SCREEN BOARD

INPUT BOARD

2

3

2

1

2

1

2

1

7

5

4

3

2

X2

FU728f

2 1

12

7

5

4

3

2

X1

FU728f

1

2

21

21

2

1

1

4

5

3

1

2

1

2

212121

2

1

2

1

2

1

2

1

2

1

2

1

2

1

21

21

21

21

1

2

1

2

2 1

12

1

2

1

2

1

54

7.11 Troubleshooting

The OM4001A power amplifier contains several protection circuits, which constantly monitor
operation of the Amplifier. When the firmware defined parameters exceed defined operating
levels, a WARNING appears in the LAST EVENTS window of the PA front panel. If some
parameters exceed a defined critical level, a FAULT is activated and the PA will automatically
switch to STBY mode. The LAST EVENTS window will then display the fault information will
appear.

All of these events are written to the FAULT and WARNING memories. The Last event is visible
after the LAST EVENTS button is pressed including information about possible causes.

There are several warning or fault messages that may appear on the display:

Warning / Fault

Action

Description

Power Out is too high

Reduce input power

Output power exceeds maximum level, reduce the
input power.

Refl. power too high

Check your antenna
Reduce output power

Reflected power exceeds maximum allowed level.
Check if proper antenna is connected. In the case of
higher SWR reduce the input power and thus the
output and reflected power will be lower.

SWR is too high

Check your antenna
Check antenna switch

Antenna SWR is too high (SWR 3 for WARNING and
SWR 5 for FAULT). Check if proper antenna is
connected. Check antenna switch configuration. If you
want to use an antenna with higher SWR, this SWR
protection can be switched off (page 25). But reflected
power will stay checked (max.350W).

Power In is too high

Reduce input power
Check amplifier tuning

PA input is too high - decrease it!
If maximum output power is not achievable, check
plate voltage and PA tuning.

Low output power
(tune)

Tune mistake.
Retune your amplifier

The PA has lower gain and may not be properly tuned.
Check the plate voltage and Screen current. If they are
ok, manually adjust for optimal tuning of the PA. (M­TUNE)

Plate current too high

Reduce input power
Check amplifier tuning
Check EBS setting

Plate current too high. Check the following:

• Too high input power – reduce it

• Improper tuning of the PA – bad antenna

impedance matching. Tune the PA properly.

• Improper BIAS setting. Check EBS1 and
EBS2.

Grid current is high

Reduce input power
Check amplifier tuning

Grid current too high is due to overdriving the PA.
Reduce the input power. If maximum output power is
no reachable due to high plate current, check the PA
tuning.

Screen current error

Reduce input power
Check amplifier tuning
Check plate voltage fuse

High screen current is usually due to the following
reasons:

• Overdriving the PA – reduce the input power

• Improper PA tuning. At maximum output power

the screen current must be inside the range of
0 mA to +80 mA

• Plate voltage is missing. Press PTT without
driving If screen current is higher than +5mA,

55

check plate fuse (page 32).

Plate voltage error

Check plate power supply

High voltage supply fault. Check the fuses on HV
board.

Grid voltage is low

Check grid power supply

Low voltage on the grid. Check fuse F9 on HV supply
board.

Screen voltage error

Check screen power supply

Check fuse F10 on HV supply board and fuse F1 on
the Screen board.

Amplifier is too hot

Check cooling system
Set up additional blower

Check the airflow (ventilation grid on the rear panel).
Cooling exhaust must be free from any obstructions.
During extended use set the blower speed to ALWAYS
ON (page 20).

HARD FAULT

Check HV circuits and Tube

Protection circuit saved HV against overload If high
current from the HV supply caused the HARD FAULT
then protection is activated and the PA is automatically
switched OFF. Check HV circuits, blocking capacitors
and the tube itself.

Heating voltage error

Set up proper transformer
voltage selector

This error is usually due to improper setting of the
primary voltage on the transformer (page 33). In
normal condition Uh readings should be 9V +/- 0,3V

Cooling error

Check blower rotation

Main blower problem. Check its functionality.

Mains error

Check mains voltage and set
up nominal mains voltage
Set up proper transformer
voltage selector

This error may be caused by the improper setting
of the nominal value of Um. Check your AC mains
voltage and set it as nominal Um (page 22,23).
Check the primary voltage setting on the
transformer. This fault may also be caused by
“soft” mains, when during transmitting the AC
voltage drops to a very low level.

56

Factory reset:

In the case of very abnormal behavior of the OM4001A it is possible to do a factory reset. This
will reset all the amplifier parameters back to the factory default values.

Press and hold the ON/OFF button and press the green Main power switch for several seconds
until the following display appears.

If you are sure you want a full factory
reset, press YES.

After the FACTORY RESET
completes the PA is ready for
operation.

Important notice: Perform a Factory Reset only if absolutely necessary to clear
abnormal behaviour, because personalized settings, mainly CAT communication with
TCVR, antenna switch settings and any USER settings must be re-input.