[VHFcontesting] 222 mhz W6PO amplifier questions

Tom k8tb at bosscher.org
Tue Dec 30 21:41:05 EST 2014

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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