I have an old EHT PSU to repair. There are 2 capacitors, one paper, one
> plywood! 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 those figures? IME pre-war paper caps are highly suspect. I'd
> rather establish what I can before subbing it, as the construction of
> the whole thing is rather characterful.
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.