Waxy substance leaking from Pilot multiplexer transformer


2008-02-13 4:47 pm

I have a Pilot FM200 (tubed) Multiplexer that has been in my possession since 1976. I have only just now tried to power it up, having just recently acquired a Variac. When I got up to about 60 volts on the variac, the unit started to make some crackling noise , and the transformer and the large coupling cap next to it got quite hot, and there was a slight burning smell. I shut the variac down and looked underneath. There is a lot of what looks like wax leaking from the transformer. Not sure if this is a fatal flaw of the transformer, or could be due to a bad capacitor(s)
that is causing the transformer problems.

My questions are:

1) how do I test the transformer to see if its bad?
I have the variac, a Fluke DMM, and a single trace scope.

2) Thinking I might need a capacitance checker also to check the filter cap. Is the capacitance checker function on a DMM from Radio Shack worth anything or do I need to get a real Capacator checker (from E-bay I suppose)

I am not experienced much with this sort of thing, I do have a EE degree, but I've been working with software, not circuits, since graduation.

I did read the FAQ about working with tube amps, and there is a cage on the top so should provide protection in case some caps explode (which I understand is possible)

I can provide pics if that helps. Thanks for any advice you can offer.