[AMRadio] Condx capacitors

w5jo at brightok.net w5jo at brightok.net
Thu Oct 13 10:19:35 EDT 2016

I would bet that if you checked the leakage of them now, you would find it 
to be excessive which puts a load on the transformer which will cause it to 
overheat Charlie.  I have had the same experience, they form good then after 
a period of time in operation they dry more and develop excessive leakage.


-----Original Message----- 

You know, I have done, or attempted to, recondition electrolytics and pretty 
much decided the results are mixed at best.  Most of the time they seem to 
recover only to fail completely after a while.  I have had a Halli S40 
receiver on the side of the bench and have been working on it's filter for a 
week now.  It's a 10/10/30 all at 450, at first, the 10uf sections would 
take the 450 without incident, the 30uf though, as you raised the volts, 
current would increase slowly, then take off up scale.  All sections take 
the full 450VDC with no problems now,   It takes the charge and holds it but 
here is the question.  A good or new electrolytic will hold a charge for an 
extended time, I charged the cap to  450 on this unit, (no loads)  and came 
back after a bit, one section had 345, one had 165, and the 30uf section had 
7 volts, measured with a VTVM.  I hit it with a charge again and it 
responded like a good cap when looking at the current draw as it was 
charged.  Under full voltag
e, all three sections together when under 450 draw less than 1ma.

To those who have had good luck reconditioning caps like this, has your 
experience given you certain signs to look for in determining whether the 
reconditioning is worth it?  Does a reconditioned cap that looks good on a 
meter, but does not maintain it's charge, indicate imminent failure?

Charlie, W4MEC in NC

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