OM2000+ - OM Power

OM2000+ - OM Power
MADE IN SLOVAKIA
OM2000+
SHORTWAVE PLUS 50 MHz
POWER AMPLIFIER
WWW.OM-POWER.COM
OM POWER, s.r.o. 93030 Báč 126,
SLOVAKIA
Contact : +421 905 321 410
e-mail : om-power@om-power.com
TABLE OF CONTENTS
1. GENERAL INFORMATION
.....................................................................
3
2.1.
Introduction
………………………………………………………………….
3
2.2.
Specification
………………………………………………………………….
3
2.2.1.
Parameters
………………………………………………………………….
3
2.2.2.
Protection Circuits ………………………………………………………………….
3
2.2.3.
Indicators
………………………………………………………………….
4
2.2.4.
Features
………………………………………………………………….
4
2. SAFETY INSTRUCTIONS
………………………………………………………………….
5
3. GENERAL DESCRIPTION
………………………………………………………………….
6
3.1.
HF part
………………………………………………………………….
6
3.2.
Power Supply
………………………………………………………………….
7
3.3.
Safety Devices
………………………………………………………………….
8
………………………………………………………………….
8
4. INSTALLATION
4.1.
Grounding
………………………………………………………………….
9
4.2.
Coaxial Cable
………………………………………………………………….
9
4.3.
Control Cable
………………………………………………………………….
9
4.4.
Main Supply
………………………………………………………………….
10
4.5.
Cooling
………………………………………………………………….
10
………………………………………………………………….
11
………………………………………………………………….
11
5. OPERATION
5.1.
Operation Elements
5.2.
Preparation for operation ……………………………………………………………….
13
5.2.1. Display menu
………………………………………………………………….
14
5.2.2. Settings menu
………………………………………………………………….
16
5.2.3. Service menu
………………………………………………………………….
19
5.3.
Operation mode
………………………………………………………………….
22
5.4.
Tuning of the Power Amplifier ………………………………………………………
23
6. MAINTENANCE
6.1.
………………………………………………………………….
27
Indication of Fault Conditions ………………………………………………………
27
1
6.2.
Fuse Replacement
………………………………………………………………….
31
6.3.
Tube Replacement
………………………………………………………………….
31
6.4.
Cleaning
………………………………………………………………….
31
………………………………………………………………….
32
7. APPENDIX
7.1.
Primary AC selection
………………………………………………………………….
32
7.2.
Removing the HV Transformer …………………………………………………….
33
7.3.
Block Diagram of the OM2000+ Power Amplifier …………………………
34
2
1. GENERAL INFORMATION
1.1.
Introduction
T
he OM Power model OM2000+ is designed for all short wave amateur bands from 1.8 to 29.7 MHz
(including WARC bands) plus 50 MHZ and all modes. It is equipped with a ceramic tetrode
FU-728F.
1.2.
Specification
1.2.1. Parameters
Frequency Coverage
Power Output
Input Power
Input Impedance
Power Gain
Output Impedance
Maximum Output SWR
SWR protection
Intermodulation distortion
Suppression of harmonics
Tubes
Cooler
Power supply
Transformers
Dimensions
Weight
Amateur Bands 1.8 – 29.7 MHz including WARC + 50 MHz
2000+ W in SSB/CW on HF bands, 1500 W in CW/SSB on 6m
1500 W in RTTY
Usually 40 to 60W for full Output Power
50 Ohm, VSWR < 1.5 : 1
15 dB
50 Ohm unbalanced
2:1
Automatic switching to STBY, when reflected power
is 250W or higher
32dB below nominal output
< -50 dBc
FU-728F Ceramic tetrode
Centrifugal blower + Axial fan
Switchable 220V, 230V, 240V, 50/60 Hz
One toroidal transformer 3kVA
390 x 195 x 370 (width x height x depth)
24 kg
1.2.2. Protection Circuits
There are several protection circuits used in the amplifier. They are activated when one or
more of next parameters exceed defined values or some unwanted occasion occurs.




VSWR too high
Anode current too high
Anode voltage error
Screen current too high
3








Screen voltage error
Grid current too high
Grid voltage error
Heating voltage error
Mistuning of PA
Temperature to high
Soft start for fuses protection
“switch-on blocking “ at opened amplifier
1.2.3. Indicators
Number of indicators visible on the front panel will inform you about value of some parameters
or operation status:
OLED display
4 x 20 characters
Analog Wattmeter
Double system meter for forward and reflected power
measuring
LED Indicators
ON AIR
STBY
FAULT
ON
– amplifier in transmitting mode
– standby mode
– failure, switching off for abt. 4 sec
– ON status
1.2.4. Features
Manufacturer implemented some of the company’s current development results with most
wanted operating and safety features into this new model:









High level of protections
Antenna switch for 3 different antennas
Memory for faults and warnings, easy maintenance
Automatic set-up anode current (BIAS) – no need to adjust manually after changing
the tube
Temperature controlled 2-speed 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 2000 W PA on the market
4
2.
SAFETY INSTRUCTIONS
WARNING!
DANGEROUS HIGH VOLTAGE INSIDE!
The power amplifier is using high voltage up to 3000V 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 NEXT RULES!
WARNING!
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!
WARNING!
Never turn the amplifier on without the upper lid in place. DO NOT ATTEMPT TO SHORT OR BYPASS
safety switch under upper lid!
WARNING!
The OM2000+ amplifier is neither to be used in a WET or HUMID environment nor to be exposed to
RAINFALL!
WARNING!
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!
WARNING!
Before opening the upper lid of the amplifier make sure that power supply has been disconnected
AT LEAST 10 minutes allowing the electrolytic capacitors to discharge fully. Disconnect power cord
from the outlet!
WARNING!
Any work inside the PA (internal fuses replacement, tube replacement, etc.) can be carried out only
by professionally qualified person!
5
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 long time
operation ventilation grid can reach high temperature. Do not touch it!
CAUTION
The amplifier must be properly grounded during operation .
CAUTION
During operation the amplifier must be installed in such a way that the rear side remains accessible.
CAUTION
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.
CAUTION
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.
3.1.
GENERAL DESCRIPTION
HF part
T
his amplifier is using a ceramic tetrode FU-728F in a grounded-cathode circuit (input into control
grids). The OM2000+ amplifier achieves excellent linearity by the voltage stabilization of the
control grid bias and the screen voltage. The power input is given 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.
6
The output of the amplifier is a Pi-L circuit. The ceramic capacitor for TUNE and LOAD are divided. 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 OM2000+
Tetrode FU728F
Antenna Switch
Output Pi-L Circuit
3.2.
Blower
Tuning Capacitor
Power Supply Board
Subpanel
Switch-ON Board
HV transformer
Power Supply
Power amplifier is using one 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 4 x 530V AC (total
abt. 2950V DC) @ 1.2A. 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 separated supply for screen grid is regulated by stabilization with MOSFET and delivers abt. 330V
DC at 100mA. Control grid voltage is also stabilized (-120V DC). Change of stabilized first grid voltage
is controlled by the software (EBS for example).
7
Type of supported TCVR and working
3 kVA toroidal
transformer
is visible
ondisplay.
the left
frequency
are visible
on the
side. Switch-ON board is in the front, Power
supply board behind it.
AUTO LED is ON.
CAUTION
Primary section of the transformer is switchable for 220 - 240 VAC. Factory setting is 230VAC. If the
AC voltage in your network is 220 or 240 Volts, you need to set the correct value before first starting
of the PA. See part 7.1. for more information.
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 element is
mechanical
for AC blocking
opened
Typeswitch
of supported
TCVR andatworking
amplifier.
frequency are visible on the display.
AUTO LED is ON.
4.
INSTALLATION
NOTE
Read this chapter carefully prior you will start installation. Before unpacking inspect shipping carton
first, if it is not damaged. Keep all of packing parts for possible future shipment. Check unpacked power
amplifier. If you find some damaging, contact your dealer immediately to keep full warranty.
During installation go step by step according to the next parts.
8
4.1.
Grounding
CAUTION
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 cross-section 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, having problems with TVI/BCI or your transmitted
signal may be distorted.
4.2.
Coaxial Cable
The output of the transceiver is to be connected to the input of the amplifier via RG58 or similar
cable. For the connection between the power amplifier and the antenna, RG213 or similar coaxial
cable suited for high power is recommended. All the INPUT and three OUTPUT (ANT1, ANT2, ANT3)
SO-239 sockets with Teflon insulation are used.
Rier view of the amplifier OM2000+
Fuses
Mains Plug
Auxiliary fan
4.3.
Grounding point
HF Outputs
Control
HF Input
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 OM2000+ have to be switched earlier than HF is applied (cold switching). Modern transceivers
they have a time delay between PTT switching and power output.
9
CAUTION
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.
The amplifier is equipped with safety devices, which ensure that the output relay is not switched under
power mistakenly (hot switching).
KEY IN
KEY OUT
4.4.
RCA Phono - Input signal PTT switching voltage / current - 5V /2mA)
RCA Phono - Output signal PTT (maximum switching of 30V / 50mA)
Main Supply
CAUTION
Be sure you got PA with properly terminated line cable, corresponding with your power system’s
outlet. If not, contact your dealer. In such a case you should make the necessary changes using a
licensed electrician.
WARNING!
Be sure that your power system is correctly wired and properly rated! To use adequately sized and
connected grounding system is also very important.
4.5.
Cooling
CAUTION
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 basic cooling of the amplifier. 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 speed (2 steps) is setting automatically according to the tube
temperature. For long time operation (contests) the PA is equipped with an auxiliary fan, which can
operate in three modes (go to Settings menu for more details).
Detailed view on the tube and blower area.
Antenna
switch
(above) isTCVR
installed
inside the
Type
of supported
and working
metal box.
frequency are visible on the display.
AUTO LED is ON.
10
5.
OPERATION
WARNING!
Before switching PA on, make sure that amplifier is grounded, antenna or dummy load is connected,
and line cord is putted to the outlet. Be sure you selected AC input by 7.1.
CAUTION
Before switching PA on, check all connections between PA and TCVR.
CAUTION
Do not turn PA on for at least 2 hours after unpacking it and locating in its operating location.
Especially when amplifier is moved from a cold place to a warm one because not visible
condensation may develop, and this could result in damage to the high voltage circuits of the PA.
CAUTION
Never try to change antenna output during a transmission to avoid warranty loss.
NOTE
When you decide to have a short operating break, place the amplifier to the standby mode rather than
switch it off.
5.1.
Operation elements
There is couple of operational elements accessible or visible on the front panel.
11
BAND
-
Band selector switch
TUNE
-
Anode capacitor for tuning
(higher frequencies to "0"; lower frequencies to „100“).
LOAD
-
Output capacitor tunes antenna load resistance to the amplifier.
Capacity is low at „100“ and high at "0" on the scale.
TUNE LED
-
WATMETER -
Three LEDs assists in tuning the amplifier
Analog double system meter for forward and reflected power measuring
ON / OFF - Long press (abt. 1 sec.) to switch PA ON/OFF
RESET
- Short press to reset faults or warnings
0/I
S1
S2
Power ON small 12V APU for logic and protection circuits
You can switch Antenna ports even if PA is switched OFF.
S3
S4
12
ON AIR - Transmitting mode LED
STBY
- Standby mode LED
FAULT
- Failure LED
ON
- PA is „ON“ LED
S1
- OPER / STBY - Press to switch between Standby and Operation mode
ESC
- Return to the previous level
S2
- MENU
DOWN
- Enter the Menu
- Scroll down
S3
- DSP
UP
- Change display (DSP1, DSP2, DSP3)
- Scroll up
S4
- ANT
ENT
- Change Antenna output (ANT1, ANT2, ANT3)
- Confirm the selection
More functions of S1-S4 buttons will be described in next parts of this manual.
5.2.
Preparation for use
The first necessary thing after connecting AC to the power amplifier is switching main (green) switch
to „ I “. Welcome message and then starting information appears on the display:
After switching main switch ON welcome
of supported
messageType
appears
shortly. TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Starting message shows which antenna is
Type
supported
TCVR
and ON-OFF
working
connected.
Toofswitch
PA ON
press
button forfrequency
abt. 1 second.
are visible on the display.
AUTO
LED isItON.
Warming time takes abt. 210
seconds.
is
possible to enter MENU during this time, but
with limited possibilities (display settings can
Typefor
of example).
supported TCVR and working
be changed,
You can change
ANTare
output,
necessary.
frequency
visibleif on
the display.
13
AUTO LED is ON.
If you change DSP during warming time, you lost count down information. Press BACK (S1) to restore
starting message.
When warming time expires, PA switches
Type of supported TCVR and working
itself automatically to the STBY mode.
frequency are visible on the display.
You have two possibilities now - switch PA to
OPER mode and start operation,
go
AUTO OR
LED to
is ON.
thru MENU and submenus to set display
parameters, some hardware parameters or to
enter the service menu.
In the STBY or OPER mode Antenna output can be changed (ANT1, ANT2, ANT3) by pressing S4. This
feature is active also if PA is switched OFF. However, the main switch (green) must be ON in order to
switch the antenna.
Display information can be changed, too.
Press S3 Type
to doof
it.supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
There are 3 different display settings possible
in the OM2000+. To set display parameters,
supported
TCVR and
go to theType
nextofpart
of this manual
forworking
more
details. frequency are visible on the display.
AUTO LED is ON.
5.2.1.
Display menu
The OLED display shows couple of parameters or texts. Display has 4 lines. Three of them are editable.
In every line user can select different parameters, using MENU. See next pictures.
14
After pressing MENU (S2) S1–S4 buttons
changed their functions. To edit display
Type of supported TCVR and working
parameters, press DISP button.
frequency are visible on the display.
AUTO LED is ON.
Press DIS1 to edit first display.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Now you can define parameters for first three
rows. Start with first line, press 1Row button.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Go UP or DOWN to select desired parameter.
Press ENTType
to confirm
selection.
of supported
TCVR and working
frequency are visible on the display.
There are 4 possible settings for the first line (one bar-graph or three pairs of different parameters):




Forward bar-graph
Forward Power _ Reflected Power
Forward Power _ SWR
Plate voltage Up _ Plate current Ip
AUTO LED is ON.
Second and third line are divided to the left and the right side, editable independently. To each of these
positions one of the 15 different parameters should be set.
If you finish first line settings, press ESC to go
back to the row selection.
Type of supported TCVR and working
To start edit second line, press 2Row button.
frequency are visible on the display.
AUTO LED is ON.
15
S2 and S3 now changed their functions.
To edit left
sideofofsupported
the second
line,and
press
LEFT
Type
TCVR
working
button.
frequency are visible on the display.
AUTO LED is ON.
Go UP or DOWN to select desired parameter.
Press ENT to confirm selection.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
If you finish left side settings, press ESC to go
back to the side selection.
Type of supported TCVR and working
To start edit right side, press RIGHT
frequency are visible on the display.
button….etc.
Second and third line programmable parameters are:















5.2.2.
AUTO LED is ON.
Forward Power
Reflected Power
Input Power
SWR
TUNE
Temperature
Frequency
Plate voltage – Up
Plate current – Ip
Screen voltage – Us
Screen current – Is
Screen current – graph
Grid voltage – Ug
Grid current Ig
Heating voltage – Uf
Settings menu
Settings menu offers EBS settings, factory default parameters restoring, display contrast settings and
auxiliary fan operating modes.
16
Electronic Bias Settings (EBS) is one of significant feature of the power amplifier. It allows to set low
plate current after pressing the PTT regardless of whether you have CW or SSB mode, until RF signal
is no present at the input. At the moment when RF signal comes to the input of PA, bias will
automatically change to its working value.
EBS level means level of the Input power, where EBS starts working. Default EBS value is 0.2 W. We
recommend using EBS ON. Significant accompaniment of used EBS is temperature reducing.
To enter Settings menu, go to MENU first,
then press SET button.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to select EBS
ON/OFF. Press ENT to enter EBS status
settings. Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Press ON or OFF to set status of EBS. Press
ENT to confirm selection.
Type of supported TCVR and working
Press ESC to go one level back.
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to select EBS level
parameter. Press ENT to enter EBS level
settings. Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to set EBS level
value. Press ENT to confirm EBS level value.
Type of supported TCVR and working
Press ESC to go one level back.
frequency are visible on the display.
AUTO LED is ON.
17
If you wish to restore factory default
parameters, use UP or DOWN button to
Type default
of supported
TCVR and
working
select Restore
parameters.
Then
press
ENT.
frequency are visible on the display.
AUTO LED is ON.
Press YESType
for 1of
second
to confirm
restoring.
supported
TCVR and
working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to select LCD
contrast. Press ENT.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to set contrast value.
Press ENT to confirm settings.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to set auxiliary fan
working condition.
Type of supported TCVR and working
Press ENT to confirm settings.
frequency are visible on the display.
LED isThe
ON.
Use UP or DOWN button to setAUTO
first mode.
fan will activate at a fixed temperature
(programmed
Type in
of uP).
supported TCVR and working
Press ENTfrequency
to confirmare
settings.
visible on the display.
AUTO LED is ON.
18
Use UP or DOWN button to set second mode.
The fan will activate together with PTT.
Type of supported TCVR and working
Press ENT to confirm settings.
frequency are visible on the display.
LED is
ON.
Use UP or DOWN button toAUTO
set the
third
mode. The fan will turn always when PA will
Type ENT
of supported
TCVR
and working
be ON. Press
to confirm
settings.
Press
ESC twice to release Settings mode.
frequency are visible on the display.
AUTO LED is ON.
5.2.3. Service menu
In the Service menu it is possible to verify software version. This menu allows user to check total
operating hours and listing in the memory, where reported faults and warning messages are stored.
You can display particularly warning messages and particularly error messages. See chapter 6 for more
information regarding to warnings and faults occurrence. There you can find a coding table together
with a limited values for the safety circuits activation also.
In the Service menu a value of EBS1 and EBS2 can be automatically adjusted. This is used for example
when it is necessary to make adjustment after replacing the tube. Automatic control of EBS, however,
can be done at any time. EBS1 default value is 20mA of Ip, EBS2 default value is 250mA of Ip.
Minimal turns of the blower are the matter of settings in the Service menu, too.
Use Service menu after replacing the tube.
This is step No. 1.
Type of supported TCVR and working
To enter Service menu, go to the MENU first,
are visible on the display.
then pressfrequency
SERV button.
AUTO LED is ON.
Use UP or DOWN button to check software
version.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
19
Use UP or DOWN button to select Time ON
parameter. Press ENT to see total operating
TypePA.
of supported TCVR and working
hours of the
frequency are visible on the display.
AUTO LED is ON.
Press ESCType
to goofback
to the Service
menu.
supported
TCVR and
working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to select Faults.
Press ENT to see fault numbers or letters (see
of supported
TCVR and working
the table Type
in chapter
6).
frequency are visible on the display.
AUTO LED is ON.
Press ESCType
to goofback
to the Service
menu.
supported
TCVR and
working
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN button to select Warnings.
Press ENT to see warning numbers or letters
Type in
of chapter
supported
(see the table
6). TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Press ESC to go back to the Service menu.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
20
Use this procedure after replacing the tube.
This is step No. 2.
of supported
working
Scroll UP Type
or DOWN
to selectTCVR
EBS1and
settings.
Press ENT to start automatic adjustment of
frequency are visible on the display.
EBS1 (20 mA).
AUTO LED is ON.
Screen voltage increases automatically during
adjustment process, grid voltage increases
Typealso.
of supported
TCVR andwhen
working
step by step
In the moment,
Ip
reaches 20mA, adjustment stops. Press ESC
frequency are visible on the display.
after stopping.
AUTO LED is ON.
Use this procedure after replacing the tube.
This is step No. 3.
Scroll UPType
or DOWN
to select
EBS2
of supported
TCVR
andsettings.
working
Press ENT to start automatic adjustment of
are visible on the display.
EBS2 (250 frequency
mA).
AUTO LED is ON.
Screen voltage increases automatically during
adjustment process, grid voltage increases
step by step also. In the moment, when Ip
Type of supported
and
working
reaches 250mA,
adjustmentTCVR
stops.
Press
ESC
after stopping.
frequency are visible on the display.
AUTO LED is ON.
Use UP or DOWN to select Calibration Ip & Is.
Press ENTType
to doofit.supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Ip and Is calibration runs in the background.
Type
of supported
TCVR and working
Result only
is visible
on the display.
are visible
Press ESC frequency
to go one level
back. on the display.
AUTO LED is ON.
21
5.3.
Operation mode
CAUTION
In STBY the amplifier is in bypass-mode and your transceiver is directly connected to the antenna.
Maximum allowed power in bypass mode is 100 Watts! Passing RF power is measured with analog
wattmeter only. It is not displayed if PA is either in standby mode or turned OFF.
Press OPER to activate operation mode.
STBY LED switched OFF.
Changing of DSP allows user to watch couple
of basic parameters of the PA in operation
mode without input RF signal. Notice: These
Type of supported TCVR and working
are three default display settings (software
version 6.1.)
frequency are visible on the display.
AUTO LED is ON.
Check all connections again. Set BAND selector, TUNE and LOAD capacitors according to TCVR
parameters and delivered tuning table (see next part for more details). Apply low input power and press
PTT. Check Analog wattmeter first. Try to tune PA for maximum output power and minimum SWR.
22
Using foot switch in „KEY IN” we
Type of supported TCVR and working
activated transmitting mode of the PA
first.
frequency are visible on the display.
“ON AIR” LED is ON.
EBS is active (Ip = 20mA) AUTO LED is ON.
In the transmitting mode all 4 buttons
(S1, S2, S3, and S4) are blocked!
Type of supported TCVR and working
frequency are visible on the display.
An example of standard tuning procedure
using Analog wattmeter.
AUTO LED is ON.
5.4.
Tuning of the Power Amplifier
The OM2000+ power amplifier is operated in class AB. Thus it’s possible to obtain a maximum output
power at excellent linearity. For this purpose the amplifier has to be tuned carefully .
CAUTION
The operation of a mistuned PA will cause malfunctions, the increase of grid current and problems
with TVI/BCI.
CAUTION
If the input power is higher than 10W and the power amplifier is NOT correctly tuned, the safety
devices will switch it to STBY. After switching the amplifier to STBY, you need to switch it back to
the OPER mode by pressing RESET button shortly.
23
A tuning table is delivered with the power amplifier. For coarse tuning select a band with BAND switch
and choose the setting of “TUNE” and “LOAD” capacitors according to the table.
Band (MHz)
Tune
Load
Input PWR (W)
Output PWR (W)
1.845
70
45
52
2000
3.630
69
51
53
2000
7.050
50
90
55
2000
10.125
72
28
54
2000
14.175
69
40
54
2000
18.150
81
48
62
2000
21.230
47
67
50
2000
24.940
61
64
51
2000
28.450
33
76
43
2000
50.200
22
90
52
1500
NOTE
Delivered tuning table was made for 50 Ohm loading of PA (dummy load). Each amplifier should have
different values depending on used frequency and used type of antenna. Make your own table valid
for your real conditions.
There are two ways how to do fine tuning. The first method uses a gradual increase in the input power
when tuning the PA (as most operators accustomed). In every case we recommend adjust the display
for both of methods so it shows two parameters important for fine tuning - TUNE and Is graph (> l <).
Press OPER to enter operation mode. Apply low input power and press PTT. Be sure you selected right
BAND, TUNE and LOAD knob positions. If you made some mistake, fault message appears:
Safety circuit stopped transmitting, fault LED
Type
of supported
TCVR
working
is ON (Fault
code
4 is saving to
theand
memory).
frequency
are visible
on the
display.
Release PTT,
set proper
positions
of BAND,
TUNE and LOAD according to the table and
press PTT again.
AUTO LED is ON.
24
Another mistake can occur, if you have antenna connected to the wrong output. In such a case „SWR
is too high“ error message appears. Change antenna output using S4 button.
This is not an optimal result, TUNE indicator
must go between both arrows. Use TUNE
knob to get maximum output power and
Type of supported TCVR and working
LOAD knob to get indicator between
arrows. frequency are visible on the display.
AUTO LED is ON.
Another example of not optimal result, TUNE
indicator must go between both arrows. Use
TUNE knob to get maximum output power
Type of supported TCVR and working
and LOAD knob to get indicator between
arrows (in frequency
arrows direction).
are visible on the display.
AUTO LED is ON.
This is a good result of tuning.
Type of supported TCVR and working
frequency are visible on the display.
Now increase input power slowly and watch the display.
AUTO LED is ON.
Two of important information is visible –
screen current increased, but still is within
the allowed limits. Turn LOAD knob slightly
Type of supported TCVR and working
in arrows direction to get TUNE indicator
between arrows.
frequency are visible on the display.
AUTO LED is ON.
Display indicates correct tuning of the Power
amplifier.Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
25
Remember
Always use TUNE knob to get maximum output power. Use LOAD knob to get TUNE indicator on the
display to the middle position between both arrows. Simultaneously check if Is graph indicator stays
within the boundaries. Repeat both steps more times.
Proper operation mode of FU-728F requires the plate voltage to be close to 3 kV. If anode voltage
without RF power is much lower, watch the heating voltage, too. Normally, heating voltage must be in
boundaries from 8.5 to 9 V without RF signal (DSP3). Heating voltage level is a reliable indicator of
correct AC selector adjustment. If you see heating voltage lower than 8.5V without RF signal, change
primary AC voltage selector one step down (if possible). Conversely, if the voltage is higher than 9V,
try to move AC selector one step up (for example from 220 to 230 VAC). Check heating voltage under
full load (full output power), also. If the heating voltage without RF signal is OK but under full load
drops more than 1.5 V, this relates to the „soft“ AC network and is solvable only by „changing“ the AC
network...
Without RF power the plate voltage is OK.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Without RF power the plate voltage is 2.85 kV.
Check the heating voltage, too. If it is below
8.5 V, this indicates the need to change AC
Type of supported TCVR and working
selector position one step down (for example
from 230 to
frequency
220 VAC).
are visible on the display.
To start the second method of fine tuning, press S2 (TUNE) button in OPER mode.
AUTO LED is ON.
PA is in the operation mode. After TUNE
button (S2) was pressed, it changes its
function. Now STOP is blinking.
Type of supported TCVR and working
Do not press STOP button yet!
frequency are visible on the display.
Apply input power according tune table (or lower) for selected band and press PTT. Use TUNE knob to
AUTO LED is ON.
get maximum output power. Use LOAD knob to get Is graph indicator within the boundaries.
26
Display shows properly tuned PA.
TUNE indicator is in the middle, Screen
current is higher, but still inside the limits.
Type of supported TCVR and working
After proper fine tuning release PTT and press STOP button. PA is now
prepared
operation.
frequency
are for
visible
on the display.
AUTO LED is ON.
View on the properly tuned PA. Analog
Type
of supported
TCVR
andreflected
working
wattmeter
shows
forwarded
and
power.
frequency are visible on the display.
AUTO LED is ON.
After this procedure the amplifier is tuned correctly and ready to give 2000 W (1500 W) output power
in all operation modes. At optimal tuning and full output power a positive max. 50mA current goes
through the second grid.
CAUTION
If the amplifier demonstrate any malfunctions during tuning or it does not behave in accordance
witch the description, interrupt the tuning procedure immediately and check the amplifier! Be sure
not to do any mistakes in choosing bands or TUNE/LOAD values! Be sure that VSWR is not higher
than 2:1 and input power is LOW!
After excluding possible human mistakes you will be able to work for long time with this amplifier!
6.
6.1.
MAINTENANCE
Indication of Fault Conditions
If a fault condition appears during the operation of the amplifier, the safety circuits of OM2000+ will
react. There are several warning or fault messages possible to appear on the display, when some of
the protection will be activated. The OM2000+ power amplifier can report one of the following
messages:
27
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
-
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
N/A
Heating voltage error
HARD FAULT
Plate voltage error
Grid voltage is low
Screen voltage error
SWR is too high
Amplifier is too hot
NOTE
Most of safety circuits are preset for two levels of exceedances. First level is a warning level. In such a
case a warning message appears on the display, fault LED will flash, but power amplifier will stay in
normal operation. See the table below for warning and fault conditions.
NOTE
When a fault condition appears during the tuning or operation of the amplifier, the safety circuits will
block transmitting and FAULT LED starts blinking. The amplifier stays in OPER mode. After approx. 1
sec the control circuits will automatically switch the amplifier back to the transmitting mode. If
problem persists, safety circuit will react again.
CAUTION
If the fault will repeat 3 times during 10 seconds, the safety circuits will turn the amplifier to STBY
mode. FAULT LED stays ON. To cancel fault status, press RESET shortly. Power amplifier will stay in
STBY mode.
All the warning and fault messages are stored in the memory. You can display particularly warning
messages and particularly error messages. See the Service menu in the 5.2.3., how to select service
display. All of messages are stored and displayed as a numbers or letters as indicated in this chapter (1
- 9; A - F). They are stored one by one to the memory. You can see them on the display in three lines,
on every second display position (maximum 10 per row, maximum 30 messages for warnings and 30
messages for errors). If memory is full, every new message will delete oldest one and move rest of
them one position back. It means that every time last 30 messages are visible on the display. Next table
shows limited values for the safety circuits activation.
Fault code
1
Parameter
Power Output is too high
2
3
4
Reflected power is too high
Power Input is too high
Low output power (tune)
Warning level
2200W
1700W (50MHz)
250W
80W
Fault level
2300W
1800 (50MHz)
300W
100W
> 3dB below*
28
5
6
7
8
9
A
Plate current is too high
Grid current is too high
Screen current is too high
N/A
Heating voltage error
HARD FAULT (from 3.1 version)
1.8A
10mA
50mA
B
Plate voltage error
C
D
Grid voltage is low
Screen voltage error
Min. 1800V
Max. 3400V
-40V
Min. 250V
Max. 400V
E
F
SWR is too high
Amplifier is too hot
+/- 2V ***
80 deg. C *****
2.0A
20mA
60mA
N/A
+/- 2.5V
Plate current >2.5A
****
Min. 1500V
Max. 3500V
-30V
Min. 220V
Max. 420V
3:1
90 deg. C *****
1. * This fault indicates mistuning of the PA. It works for Input power higher than 10W. If output
power decreases more than 3dB below value corresponding with the applied Input power,
fault message „Low output power“ appears. You have to tune the PA correctly.
2. *** When the heating voltage exceeds boundaries 9V +/- 2V, warning message „Heating
voltage error“ appears. Check proper position of AC selector (page 25). Heating voltage
without RF signal should be between 8.5 and 9V.
3. **** „HARD FAULT” appears if the plate current exceeds 2.5 A. In such a situation hardware
will immediately disconnect high voltage from the plate. Fault is signed with the letter „A“ in
the memory. If error occurs frequently, consult this situation with the manufacturer, please.
4. ***** If temperature sensor inside the PA detects of 80 deg. Celsius, warning message
„Amplifier is too hot“ appears on the display. At 90 degrees protection circuit will
automatically block transmitting (fault condition). You have to decrease the power or wait
couple of minutes to be ready transmitting again. Fault is signed with the letter „F“ in the
memory.
An example shows situation when Input
power is too high. By pressing PTT safety
circuit will react quickly, error message
appears and FAULT LED starts blinking. In
this case Type
screen
ofcurrent
supported
exceeds
TCVRlimited
and working
value (60mA).
frequency are visible on the display.
After abt. 1 sec. PA returns to TX mode.
Reduce Input power to avoid fault repeating.
AUTO LED is ON.
29
This is the situation, when problem with high
Input power persists. Safety circuits reacted
3 times, and then switched PA to STBY mode.
Permanent fault appears.
Type of supported TCVR and working
To return PA to the normal operation,
decrease Input
power
then
fault
frequency
arefirst,
visible
onreset
the display.
status and go back to the OPER mode.
AUTO LED is ON.
If resistor R1 or fuse F3 is damaged, safety
circuit stops starting of the PA and fault
message appears on the display. It is
necessary to replace the damaged
component.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Fuse F3
Resistor R1
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
If there is a fault condition, always try to remove the cause first. If it is not a hardware failure, it usually
succeeds. For example high VSWR, high Input power, mistune of PA, high temperature, etc.
In the case of some hardware failure or if your power amplifier is not working properly, please contact
the manufacturer or your dealer.
WARNING!
Never try to change or move any part inside the amplifier except of tube or fuses. Substitution of
parts may void intrinsic safety!
Manufacturer’s contacts:
OM POWER, s.r.o.
930 30 Báč 126
SLOVAKIA
Email: om-power@om-power.com
30
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 person! Internal fuses are located mainly on the SWITCH-on board (next to
the HV transformer).
One special fuse is used in the model
OM2000+. In the case of an accidental
discharges in the tube this fuse saves HV
supply circuits.
Type of supported TCVR and working
frequency are visible on the display.
Fuse
AUTO LED is ON.
6.3.
Tube Replacement
In the case of vacuum tube damaging, contact the manufacturer or your dealer for ordering new one.
You will get instructuions how to change it. Exchange can be carried out only by professionally
qualified person! After tube replacing automatic BIAS adjustment must be done. Read Service menu
(5.2.3.) and pictures on page No. 20 for more details.
6.4.
Cleaning
To prevent damage to amplifier surface and plastic components do not use aggressive chemicals for
cleaning. Do not open the amplifier for cleaning. Outer surface may be safely accomplished by using
piece of soft cotton cloth moistured with clean water or window cleaner.
31
7.
7.1.
APPENDIX
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 of the PA we recommend to check the correct value
according to the AC voltage in your network. Change the settings, if necessary.
Side view on the opened OM2000+
HV Transformer
AC Selector
Remove the upper lid first. On the right side of the PA, next to the HV transformer there are two PCBs
mounted. On the left upper side of the front (Switch-ON) board connector J6 is located.
Use flat screwdriver or finger and press
carefully the white stick to release contact
and move upper end of the white jumper to
the proper position, if necessary.
Jumper must be connected between bottom
contact and
of remaining
contacts.
AC
Typeone
of supported
TCVR
and working
voltage is marked next to every contact.
frequency are visible on the display.
AUTO LED is ON.
32
NOTE
AC selector range can be changed in the production according to the specific conditions in individual
countries.
7.2.
Removing HV Transformer
For simpler and easier transport of the PA, HV transformer can be removed and taken separately. This
distributes the weight of the PA (24 kg) about half and half. Follow next steps to do it.
1.
2.
3.
4.
Remove upper lid from the PA.
Turn the PA on the left side (transformer is up).
Disconnect 3 connectors from the front board and 1 connector from the rear board.
Release 4 screws from the bottom side of the PA. Use Philips screwdriver P2. During the release
of the last 2 screws hold the transformer by hand. Do not worry about its weight, it will move
down just 1 cm and remains on the central rung of the PA.
5. Use both hands to take transformer away from the chassis.
Watch the released terminals, when moving
the transformer!
Do not damage transformer insulation during
removing and transportation.
Type of supported TCVR and working
frequency are visible on the display.
AUTO LED is ON.
Weight of the PA was distributed (transformer
has 12 kg, rest of the PA has cca 12 kg, too).
Type of supported TCVR and working
frequency are visible on the display.
When refitting the transformer, watch to the correct location of individual sections and wires.
AUTO LED is ON.
NOTE
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.
7.3. Block Diagram of OM2000+ Power Amplifier
33
34
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising