On 08/22/2018 06:12 AM, Cursitor Doom wrote:
On Tue, 21 Aug 2018 21:28:10 -0400, Phil Hobbs wrote:

+1 for can-opening it to save wear and tear on the board. If you
measure 45 ohms ESR in-circuit, it won't be better by itself.

Well, it's hardly surprising for an electro of this age. Clearly the
original component from a scope with a s/n indicating it was manufactured
44 years ago! What was more surprising was that only 2 out of 6 electros
in the PSU section showed abnormal readings (the remaining faulty one has
gone leaky).

I have a Keithley 410 Micro-Microammeter from about 1960 that has all
its original electros and still works fine. Of course it uses an
electrometer tube, so it takes a good couple of hours' warm-up to settle
down on the 100-fA FS range, but it eventually does.

It has way more soul than my 610C(*), but really isn't nearly as good a
meter. (Don't anybody tell it, though--it has an honoured place on my
bench shelf.)

Cheers

Phil Hobbs

(*) "Now Nortons and Indians and Greeveses won't do...They don't have a
soul like a Vincent '52." -- Richard Thompson

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com