[R-390] Recapping question

[Tim Shoppa]

Barry mentions:
> I'm replacing some high resistors in the crystal deck and in the
process, 
> am replacing some of the bypass caps.  I suspect they could be
partially 
> responsible (due to leakage) for the resistors going high.  They are 
> the "Erie" brand disk ceramics and their outside surfaces have turned
to a 
> sticky, waxy feel which make me think they could be comprimised (not
sure 
> about that).  I decided that while I was in the area I'd replace them.

My two cents, which you will note is about things that you did NOT
actually ask questions about!

1. Those resistors drift up no matter what. If they're charred
or burnt or toasty, it's typically because of a past (probably
decades-past!) tube fault. Replacing them to put them back
into spec is fine if you're in there, hopefully with
something that won't drift back up over the years and
will also withstand overload better than carbon comps!

2. Waxy disk ceramics do not indicate any problem. When I
started tinkering with tube radios in the 60's those ceramics
were waxy when nearly new! Disk ceramics that are vaporized,
or disk cermaics that are burnt in two, or disk ceramics lacking
any covering are usually more obvious clues that something
isn't right! You don't often see these failure modes of disk
ceramics in receivers although they happen in spades in
transmitters.

Tim.