[Drake] TR7A PA Oscillations

[Darrel Nichols]

My late serial TR7A recently began acting up on 40M.   Only on 40, =
either phon or CW, will go
into oscillation and peg the wattmeter both forward and reverse.   =
Strange thing is, only does
this with a transmatch in line.   Straight into an antenna even with =
high SWR, works OK and is
good into a 50 ohm load.  PIN diodes check OK.

Tried different tuner, cables, different lengths etc.   It does it with =
or without the ground connected.  =20
Other rigs, both tube and solid state are OK on the same antenna.

Must be something I am overlooking.   Anybody have any ideas?

Darrel, N=D8DBX


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