Re: capacitor testers OT

Bert Haskins

On 3/14/2020 7:37 AM, greenboxmaven via Groups.Io wrote:
The Sprauge "Telohmike" condenser tester is one of the best ever made for condensers  in tube circuit voltages. The general design was used by Heathkit and Eico, as well as at least one miltary version. They are very good for re-forming electrolytic condensers, you can easily monitor capacitance, leakage and ESR as the reforming proceeds. It's strange how Sprauge made an excellent instrument, but some of the worst condensers of all time. You don't need anything but your eyes to find a bad "Bumble Bee" or "Black Beauty" condenser, if it's there, it's bad. I know a few might still be good, but it's not worth risking a power transformer, scarce tube, or other components.

       Bruce Gentry, KA2IVY

On 3/13/20 11:49 PM, John Griessen wrote:
On 3/13/20 12:57 PM, Bert Haskins wrote:
I also have a 70+ year old Heath "magic eye" capacitor tester that
I use for leakage tests.

I bought this when I was fifteen for use in repairing guitar amps.

It is still quit useful today.
I have a GR cap bridge with magic eye.  I think mine needs some repair.  I gave it a quick test when I got it
and seemed broken.  What is that magic eye tube displaying on a cap tester?  How does it differ from a meter
moved by a null detector amp?

As a prime example of a really stupid design, when Heath copied the design of the Sprauge they skipped the line fuse..

When the filter cap shorted it was the end of the power transformer.

Three guesses how I found this out.

I've been searching for years for a replacement transformer for my first one.

Needless to say I put a fuse in my second one.

-- Bert

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