I have an old EHT PSU to repair. There are 2 capacitors, one paper, one ply wood! The paper cap, which is uncased, tests as: 420nF 11 ohms ESR, 5% loss . I've not yet done a dc leak test, which it needs. What do you think of th ose figures? IME pre-war paper caps are highly suspect. I'd rather establis h what I can before subbing it, as the construction of the whole thing is r ather characterful.
NT
I've a few boxes full of oil/paper metal-cased capacitors I could test for comparison purposes if needs be, Tabby, but I've added s.e.r in case some kind soul there will know the answer off the top of their heads first.
thanks. It's the loss rather than ESR I don't know enough about, I have a r ule of avoiding paper caps whenever possible. ESR varies greatly depending on construction details. And I wouldn't be surprised if all your canned pap ers are leaky. Hopefully I'll get the time soon to go back to this PSU.
NT
There's an interesting thread over on s.e.r at the moment on paper caps; you should take a gander at it.
Pre- which war?? :-)
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