[Heathkit] IO-12 O-scope

[kd4e]

> I have a Heathkit IO-12 scope that after warm up the
> trace disappears. Any suggestions on where to start
> looking for the trouble? 
> Thanks Barry, KF5GC

It is really old and tired?  :-)

Seriously, have the original electrolytics been replaced?

Have you check the tubes to see if any have gone soft?

Also, you may want to look at larger dropping resistors
that under thermal stress may have drifted significantly
enough out of tolerance to negatively impact performance.

We've been chasing these things in an old Knight TR-106
and it is amazing that as to replace one bad/weak component
how others suddenly show up!

-- 

Thanks! & 73,
doc, KD4E
... somewhere in FL
URL:  bibleseven (dot) com