Hi-
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.
Kirk
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.
Kirk
If it's been laid up for that long this thread may be of interest to you.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=71056
http://www.diyaudio.com/forums/showthread.php?s=&threadid=71056
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