"gareth" wrote in message
...
Having now borrowed my friend's Variac, what is seen as
good practice for ramping up old valve radios to reform the
capacitors?

Start off at, say, 50VAC and then increase by 50VAC every
1/2 hour until 240V is reached?


Thank-you to all who replied for the hints and tips.

The comments by Michael about ESR only being of real concern for
high frequency switchers was interesting.

What I shall do is, firstly, remove all the valves ("tubes" to the W and VE
contributors :-) ),

Then, because initial continuity checks suggest some discontinuity around
the incoming mains, do some disassembly, because although the chassis
is spacious and generally well laid out, it is crammed in around the mains
transformers such that even my dentists' mirror cannot see around the
corners.

The "rectum friers" seem to be silicon ones, so, as I will already have done
some dissassembly in that area, I plan to put a 100k resistor between the
rectifiers and the reservoir capacitors (should that be,"condensers" if an
old set?) and then bring up slowly on the variac.

Hopefully there will not be too much vapour (q.v.) in this project!