A surprising result tonight.? ?I found a yellow toroid T2-25 I think, put 22 turns of magnet wire on it, and verified with ancient MFJ259B that it was > 650 ohms reactance in the 40-60 MHz range.
Tried putting that in series with L201, figuring it could reduce the "inflow" if the bypass was via L201/L202.
It did NOTHING to help.? ? In fact, even DISCONNECTING L201 did not change the "bypass" around the filters.
What I did notice, however, was that the "bypass" was 10+ dB? ?STRONGER when the unit was UNPOWERED, than when it was powered.? ?The result was striking.
I'm injecting tracking generator at C205/C206 (having disconnected the output of T7 PA XFMR) and looking at what gets to the ANTENNA connector.? ?
There is MORE getting there when the unit is unpowered, than when it is ON and RECEIVING.
This makes? me wonder about the other path --- through the voltage doubler to the "HV" designated point on the schematic, and then from there to R216 and thence through inductor to the output.? ? This just doesn't look terribly likely, but there are not many possible paths left!
Gordon KX4Z
