Recommendations needed for capacitance tester.

[gtrplayr1976]

Any recommendations for a capacitance tester ? Not too expensive please

Thanks All !

[Miter53]

Tenma Capacitance Meter | 72-8150 (728150) | Tenma

I have one of these and it works great. Zero adjust helps in measuring very small caps.

[gtrplayr1976]

Tenma Capacitance Meter | 72-8150 (728150) | Tenma

I have one of these and it works great. Zero adjust helps in measuring very small caps.

Does it perform leakage ,and ESR ? I have one that will measure a capacitor ,but won't tell me if it's any good.

[g1]

That would come down to what you consider "too expensive".
There are some discussed here:
http://music-electronics-forum.com/t38166/

or you can make your own like this:
http://conradhoffman.com/cap_bridge.pdf

[gtrplayr1976]

That would come down to what you consider "too expensive".
There are some discussed here:
http://music-electronics-forum.com/t38166/

or you can make your own like this:
http://conradhoffman.com/cap_bridge.pdf

Thanks g1 , So you got one of these DER EE DE-5000 ? How do you like it ? $100 is reasonable. I see some of the vintage green eye testers for $70-80 ?

[g1]

I like it. It's capable of doing much more than I'll ever need it for, but I like being able to check ESR, and the odd time it comes in handy to be able to measure inductance.

[Enzo]

A meter that measures the capacitance is the most basic, and the least helpful. I have a B&K cap meter. I get it out once every few years to verify that some small cap is either 82pf or 820pf when it has "820" printed on it. When electrolytics dry out, sometimes their capacitance reading goes high. but normally caps don't drift off to some odd value.

ESR can be informative for filter caps.

But the main problem with caps in an amp, a tube amp anyway, is leakage. And that can only be done at working voltages. Little hand meteres use a volt or two to test a cap. A cap might measure fine for value, but it might test great at the meter voltage, but leak like a screen door at 100-200v. And that sucks if it is a 450v cap in a 400v circuit.

I have an ancient Eico 950B, and I use it more than anything else. To be honest, I usually test caps by their performance in circuit. A cap tester is more for characterizing caps out of old stock. If I have to test a cap that is in a circuit, I probably already know it is bad by simple substitution methods. But the 950B (and the other similar units) can put all the way up to 500v on the cap under test. The magic eye tube shows visually how leaky the cap is.

Especially if you already have a cap value meter, I highly recommend one of the old magic eye units. Some info:
Tube-era capacitor analyzers - Part Two; Knight, Eico, Lafayette, Heathkit
EICO 950B Bridge Capacitor Tester (1965)

Looking on ebay I see a bunch of them, and even if they don't work, they are still a bargain and always repairable. And that is just the one brand and model.
Eico 950B Resistance Capacitance Comparator Bridge

Here is one that costs more but looks fancier. it tests leakage up to 100v at least, but I want at least 400v for testing on my bench.
B K Capacitor Analyst 801 | eBay

The Sencore Z-meter units will do it all, but will cost a lot more. But they will directly measure inductance as well as capacitance, so if you do a lot of crossover repair, that might be a factor.

The old Sprague Tel-Ohmikes are classics, and cost a bit more than the Eico and Heath units, but are somewhat fancier. On ebay also.

[olddawg]

As I have mentioned before. In a busy shop I usually recommended testing suspected caps by replacement. We had a big expensive Sencore tester that would test caps at operating voltages. I finally put it on my bench because I thought someone would hurt themselves with it. It was too complex to set up for a lot of the techs and easy to overvoltage caps on it creating explosions. Honestly I've had ESR meters, etc. The capacitance function on most multimeters is fine for quickly verifying value. In the end I found it easier and more efficient to just replace any suspected caps.

[gtrplayr1976]

Thanks folks ! I bought a Heathkit C2 ,so hopefully it will do what I need.

[nickb]

This might come in handy..

[gtrplayr1976]

This might come in handy..

Thanks nickb !

[gbono]

Fluke, Keysight, etc. want you to remember that a DMM is also useful in testing a capacitor

How to measure capacitance with a digital multimeter

[gtrplayr1976]

Fluke, Keysight, etc. want you to remember that a DMM is also useful in testing a capacitor

How to measure capacitance with a digital multimeter

I have a meter to read value. I wanted something to check ESR

[gbono]

I have found that the ESR meter I have is more useful for testing batteries than verifying the quality of a capacitor in circuit. Much faster to sub in anther capacitor or do as Enzo says - look at the voltages around the in circuit capacitor.

https://www.youtube.com/watch?v=Lq9-9A8kn8Q

or check out this comparison

https://www.youtube.com/watch?v=ESijVVY_GjA

[gtrplayr1976]

I have found that the ESR meter I have is more useful for testing batteries than verifying the quality of a capacitor in circuit. Much faster to sub in anther capacitor or do as Enzo says - look at the voltages around the in circuit capacitor.

https://www.youtube.com/watch?v=Lq9-9A8kn8Q

or check out this comparison

https://www.youtube.com/watch?v=ESijVVY_GjA

I'm trying to find the cause of a xfmr failure. Tubes tested good ,and some filter caps were replaced. I thought maybe I could test the other two caps that COULD be filter caps to see if they have failed. They show no signs of it though. They look new.