[Drake] TR4C unwanted carrier

[Dick KF4NS]

Hi Guys,
This is a repost of the one I sent over the holidays. Must have been a 
bad time to send it. Got no replies.

"I just had my first lengthy QSO on 20M SSB since the restoration. A
problem has popped up that was not an apparent trouble while doing all
the testing on the bench.

After about a full minute of transmission the wattmeter starts showing
a gradual climbing of carrier on the SSB signal. I have very good air
flow, carrier balance was set during rehab, the finals were
neutralized. Power output is over 200W with plate current reading
around 500ma.

This does sound like a heat problem but as I said, there is plenty of
air flow in and out of the rig. I have not tried lowering the output
yet to see what that does but just wanted to put this to the groups
ASAP before I do any damage. I know that one of the filters is bad but
the 9mhz OSC. was tweaked with C130 to a satisfactory balance which
left the CXR OSC still very close to 9MHZ. Let me know your thoughts."

73, Dick KF4NS
St Petersburg, FL 33714 USA