[R-390] Noise when warm ('390A)

[Tim Shoppa]

> "frying bacon" or "snap-crackle-pop" [after a few hours]
> What is the concensus...more likely a cap or a tube?

The tubes get up to operating temperature within a few minutes
of power-on.

I would begin to suspect arcing over in the chokes or transformers.

See if turning the rf gain all the way back to low gain makes the
problem go away or if it stays there.  If it stays there, it's probably
something on the AF deck (which has plenty of transformers, chokes,
capacitors, etc.)

One of my two R-390A's has this and I've traced it to the Limiter
switch on the chassis.  Snap-crackle-pop only when the limiter is off.
I suppose it could be some part in the limiter stage though I suspect
that stage is pretty much supposed to be bypassed when the limiter is
off.

Tim.