Cap reforming

WOPL Sniffer

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#1
Sorry Ed to be beating a dead horse but I was reading up on the theory of reforming of Capacitors and you may have already answered this but the volume of information here is amazing. Anyway, here goes it.... I am under the impression that the initial powering up of a capacitor forms the oxide layer and over time, this layer can break down and indeed need regeneration. Some equipment manufacturers recommend the regeneration of capacitors if they have been sitting for a year or more and some manufacturers don't even address it.

Q: If I buy a new set of caps dated Jan 2015 and install them today, is reforming needed or just recommended?

Q: I went through basic and advanced electronics in the Navy and we would get caps out of supply that were packaged in the 40's through the 70's. We were never taught this "reforming" technique. Never had a problem with a radio blowing up during power up after repair, is it a "High Power" thing?

Thanks

Perry
:tard:
 

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#2
Will a "Capacitor Tester" suffice for the reforming or is the 100VDC PS the better way?

Quote from an article on the web: Not all capacitors can be raised from the dead. If you have a tube electronics item that operates fine for several weeks, months, or even years and then goes out and you trace the trouble to a filter capacitor it is not very likely that you can recover it. A capacitor which has failed in operation is a goner and you might as well replace it. The capacitors that are just sleeping are those that have not been used for many years. That applies whether they are installed in a piece of equipment or are still in the box. NIB (new in box) or NOS (new old stock). An electrolytic capacitor that hasn't been used for 30 years or more will lose most of its forming.
 

orange

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#3
I've never found such a situation specifically and I probably don't know what to look for but I've been on antique radio groups since the late 90s and the consensus is often it's more of a time wasted.
 

laatsch55

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#4
Check the WOPL archives....there's a thread dedicated to cap forming reforming by Gepetto.
 
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