User's Manual

30
After described procedure the amplifier is tuned correctly and ready to give 1500 W PEP output
power in all operation modes. At optimal tuning and full output power a positive max. 20mA current
goes through the second grid.
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 antennas, bands or segments! Be sure
that VSWR is not higher than 3:1 and input power is LOW!
After excluding possible human mistakes you will be able to work for long time with this amplifier!
6. MAINTENANCE
6.1. Indication of Fault Conditions
If a fault condition appears during the operation of the amplifier, the safety circuits of OM2000A+ will
react. There are several warning or fault messages possible to appear on the display, when some of
the protection will be activated. The OM2000A+ power amplifier can report one of the following
messages:
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 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, but power amplifier will
stay in normal operation. See the table below for warning and fault conditions.
When a fault condition appears 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
problem persists, safety circuit will react again.
If the fault will repeat 3 times during 10 seconds, the safety circuits will turn the
amplifier to STBY mode. To cancel fault status, press STBY/OPER shortly. Power
amplifier will stay in STBY mode.