Motor run/start capacitors

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xtian
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Motor run/start capacitors

Post by xtian »

A very generous gentleman called me after seeing the article about my amp building activities, and offered to give me some old junk. Morgan Jones books, two matched quads of EL34, half dozen new 12AX7s, RCA tube caddy, etc. Wow.

Included are some oil can caps, Motor Run or Motor Start type, which I was just reading up on wikipedia. He said they're often used in hi-fi builds because very low ESR. They are dated 2009 and 2010. They're too big to use in a guitar amp. Are they still good? Sell on eBay? Make a rail gun?

And look at those beige, square, Russian caps, 0.015uF. Anyone seen those before?
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didit
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Re: Motor run/start capacitors

Post by didit »

By what measure are they "too big"?

Best .. Ian
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Leo_Gnardo
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Re: Motor run/start capacitors

Post by Leo_Gnardo »

xtian wrote: Sun Apr 23, 2017 8:02 pmAnd look at those beige, square, Russian caps, 0.015uF. Anyone seen those before?
Kooool! Good on ya. I avoid publicity, figure it will just bring on OSHA, EPA and other nosy nincompoops.

I think those russki square caps are mica. They have their fans in the hi fi zone, get some mentions over at Audio Asylum. How about the cylinders in the foreground, they look like russki teflons, also favored by some wild eyed hi fi types. I'm sure you'll be finding out whether they work well in guitar amps.

Motor run caps perfectly good for DC filters. Motor start, not so much, they're intended for intermittent use. I doubt those motor runs will ever go bad. They used to be made paper in oil style but in recent times polypro film seems to have taken over. You may be able to look up part numbers and find out for sure.
down technical blind alleys . . .
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xtian
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Re: Motor run/start capacitors

Post by xtian »

Leo_Gnardo wrote: Mon Apr 24, 2017 2:11 amI avoid publicity, figure it will just bring on OSHA, EPA and other nosy nincompoops.
Say, whuzzat now?


Leo_Gnardo wrote: Mon Apr 24, 2017 2:11 amI think those russki square caps are mica. They have their fans in the hi fi zone, get some mentions over at Audio Asylum. How about the cylinders in the foreground, they look like russki teflons, also favored by some wild eyed hi fi types. I'm sure you'll be finding out whether they work well in guitar amps.
Thx, Leo!

Here's a better look at the parts numbers. Google is failing me--can you tell if these are start or run caps?

Smaller silver one has teflon ends, so I'd say you spotted it!
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ToneMerc
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Re: Motor run/start capacitors

Post by ToneMerc »

xtian wrote: Mon Apr 24, 2017 3:29 am -can you tell if these are start or run caps
The high values tell me they are start caps;none of these caps last forever anymore as you can't use the really good insulating oils, you know the stuff that causes cancer, blindness, upset stomach, suicidal thoughts, drowsiness, kidney/liver damage, baldness and male breasts .....LOL

TM
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