Without any power, look at the return loss (swr) of the input. Use an
antenna analyzer, connecting the input to the antenna port.
Theoretically, you can do the same with the output circuitry, again,
with the amp powered down. You should see the resonant spot. Many times,
in FM broadcast rigs, they seem to tune up, but not nicely, and I find
them to not be on frequency. I looked at a friends 1296 amp and found
the tank to be resonant almost 200 Mhz away. Today we have relatively
inexpensive test gear to look at this. See if both the input and output
are resonant at 222 Mhz.
Tom, K8TB
On 12/30/2014 8:39 PM, mike repinski via VHFcontesting wrote:
I recently finished a 222 mhz amplifier. I get 1500 watts input and 200 watts
out. Not very efficient :( Could anyone shed some light? Not very
complicated, not sure if I am missing something? Mike
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