TU56/TC11 restoration - VARIAC question
bfranchuk at jetnet.ab.ca
Fri Mar 18 12:53:12 CST 2005
>What you are saying is consistent with what I see on most sites selling
>these things. There, "run" caps are generally oil, and "start" caps are
>generally electrolytic. The exception being the occasional "start/run" cap,
>whatever that is.
>The original caps in the TU56 are high capacitance, and clearly
>electrolytic. But they appear to be wired for continuous phase shifting
>duty. Hence some of the people on the list insisting that they are "run"
>caps, and that the beefier, more expensive "run" cap should be used.
>Finding a 100uf oil-filled "run" cap is not easy, and they tend to be
>expensive (as Jay pointed out).
Well they are more around I think do to the vacumm tube audio field and
may want to look there.
http://www.percyaudio.com/ some nice NEW caps here. Still about $50
>The TU55 uses a 7uf oil capacitor in this role, which again argues for a
>"run" capacitor, except the values are wildly different. Is it possible
>"start" caps were used in the TU56 to save $$, but are being derated somehow
>so they can be used as "run" caps??
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