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Capacitance Meter Recommendation

I'm just starting the process of bringing back from the dead a very old

1950's RCA color television. The CTC-7 chassis is very ugly looking, with over 75 paper capacitors. There are also two Sprague can-type electrolytics, 3 caps in each can. Will have to make something to replace. Powering on is out of the question until I can replace numerous components.

I want to buy a capacitance meter to check both the caps that I'm replacing and the replacement parts I will install. I've been looking at a BK Precision 810c Capacitance Meter. Or maybe I'll buy a Fluke 177. But then I read this from a post in 2002:

"don't expect the Capacitance measurements (of a DMM) to equal that of even the cheapest C meter. Even on the "expensive" meters." Paul Grohe, sci.electronics.basics

My concern is that the capacitor checker function built into a multi-purpose DMM isn't as good as a stand-alone capacitance meter. Is there any truth to this statement?

Reply to
Nomen Nescio
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Nearly everyone who is into restoring old radios or TV's (myself included) replace all of the paper caps with polypropylenes or mylars and all of the electrolytics with new ones. If one of them is still good, it is likely to fail soon, so why not just replace them all?

Do that and you do not need a meter as the new caps are surely good.

But, if you really want a cap meter I can offer the ESR60 which measures ESR and value at US$149.00. See

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for details.

John The Electronic Repair Center at

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Reply to
John Bachman

If you want to verify electrolytic capacitors, you have to be able to check the ESR.

Tom

Reply to
Tom MacIntyre

First we have to establish that we are talking about two very different applications: old TV/radio restoration and ESR.

When your TV was designed no one worried much about ESR, it just was not an important characteristic of capacitors, electrolytic and otherwise. So ESR measurement is not a big deal in those situations. I only mentioned it thinking that you might have other applications in which ESR measurement would be useful.

You are correct in that ESR is affected by other components in the circuit. Most ESR measurements are made on electrolytic filter capacitors, not frequency sensitive circuits. In those case, the ESR can be measured in-circuit as long as the meter does not forward bias any semiconductors in the circuit. Not a problem with 50's TVs :-)

John

Reply to
John Bachman

See my post to your other question.

Yes, the ESR60 will not measure the value of the paper capacitors you are dealing with.

John

Reply to
John Bachman

Surely you would replace all those caps as a matter of course, as well as the high value resisters

David

Nomen Nescio wrote:

Reply to
quietguy

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