OM POWER OM2000+ User Manual page 27

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...
To start the second method of fine tuning, press S2 (TUNE) button in OPER mode.
Apply input power according tune table (or lower) for selected band and press PTT. Use TUNE knob to
get maximum output power. Use LOAD knob to get Is graph indicator within the boundaries.
Remember
Without RF power the plate voltage is OK.
Type of supported TCVR and working
frequency are visible on the display.
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 220 VAC). frequency are visible on the display.
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.
AUTO LED is ON.
AUTO LED is ON.
AUTO LED is ON.
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