Hi Marcel: My 425 also indicates 1.8 "Plate Kilovolts" on the front panel
meter. I was suspicious when that started, about five years ago, since the
drive wattage and Tune/Load settings remained the same for the same power
output so I checked the actual HV out of the power supply.
CAREFULLY!!!
My power supply itself puts out 2,320 Volts when the plate meter sits on the
dot between the numbers 1 and 8 in the 1.8 red scale. Running CW with 1500 W
measured output the actual voltage drops to 2,230 V - while the meter on the
Titan drops to just a bit to the left of the 1 in 1.8. I suspect a dropping
resistor in the metering circuit, but I haven't been curious enough to tear my
setup down to get to the circuitry. Too much work for too small a concern.
Now, I was suspicious for three reasons. Besides the fact that my logged
settings for max output had not changed, local hams who can hear me very well
and know my voice report NO AC HUM on my signal with or without the amplifier
in line. And the final reason is that when the filter caps go bad there's
usually a very substantial drop in voltage between no load and full load.
If you don't show a big drop in HV between idling and operating I would not
worry too much about it. If it worries you find a calibrated high voltage meter
or a probe that will work with a meter you have and measure the HV at the power
cable at the back of the RF deck. And have everything hooked up and metering -
AND YOUR HANDS WELL CLEAR - before you turn the power on! Failure to do this
can result in a well done ham!!!!
If the HV meter agrees with the built in meter, you may have a power supply
problem worth fixing. If it reads much higher than the built in meter you
probably have a voltage divider problem in the Titan's metering circuit.
73 Pete Allen AC5E
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