[AMPS] AL-1200 problem (self-oscillation?)

[Jim Reisert AD1C]

I'm having a new problem with my new AL-1200.  The tube seems to go into
some sort of self-oscillation, even if you just turn the power on.  It
makes some sort of clicky noise on 10M (as if it were arcing), and the air
flow gets very warm.  If I try to drive power into it, the output power
fluctuates wildly, from nothing to full power and everywhere in between.

It doesn't always do this, and it seems to stop sometimes, and the amp
works just fine as if there is no problem.  I tried reseating the tube and
that had no effect.  I looked inside the RF deck while it was happening and
didn't see any arcing.

Does anyone know what might be going on?

Thanks - Jim AD1C

--
Jim Reisert AD1C <jjreisert@alum.mit.edu>      http://jjr.ne.mediaone.net/


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