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Old 02-17-2018, 06:42 PM
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Dubis7 Dubis7 is offline
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WTB: Vintage Capacitor Tester

Hi all,

I'm planning to revisit a tape recorder repair that may be suffering from a bad capacitor of a type that doesn't usually go bad. Problem is, I don't have a capacitor tester, and I have zero knowledge on what to get. I've heard that the vintage ones are better, and not just because of the standard resiliency from older equipment, but those also seem to cost hundreds of dollars unrestored. If anyone has any recommendations, or a restored unit they're looking to sell, I'd be interested in talking to you. Thanks!
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Old 02-17-2018, 07:25 PM
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Electronic M Electronic M is offline
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Depends on the value range and what you want to test...Pf stuff (especially low pf) you will get a more accurate capacitance from a modern $15 Chinese ESR tester of ebay.

If you want to test for leakage (best done at rated voltage) an eye type tester like a Heathkit C-3 is best...They can also be accurate for capacitance down to the mid-pF range....C-3 testers have IIRC 2 lytics and 3-4 paper caps. You may also want to change the resistors...They are usually as easy or easier than an AA5 to restore.
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Old 02-17-2018, 10:36 PM
mrjukebox160 mrjukebox160 is offline
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https://www.ebay.com/itm/Heathkit-Co...4AAOSwg31ahmdw
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Old 02-18-2018, 11:33 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by Electronic M View Post
Depends on the value range and what you want to test...Pf stuff (especially low pf) you will get a more accurate capacitance from a modern $15 Chinese ESR tester of ebay.

If you want to test for leakage (best done at rated voltage) an eye type tester like a Heathkit C-3 is best...They can also be accurate for capacitance down to the mid-pF range....C-3 testers have IIRC 2 lytics and 3-4 paper caps. You may also want to change the resistors...They are usually as easy or easier than an AA5 to restore.
My Chinese ESR tester doesn't seem to read under 100pf or so.
I test my paper caps using my variable DC power supply and my digital multi-meter set on the milli-amps range. The DC supply goes up to 400 volts.
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Old 04-04-2018, 02:34 PM
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Tubejunke Tubejunke is offline
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I have a number of Heathkit C-3s that need to go (just too many). I was going to recap them and sell or use, but I just never got around to it. All are good meaning they all have good power transformers, switches, potentiometers', and magic eye tubes. Some even have new power supply electrolytic caps from my testing. You can actually just recap the test under load circuitry (if not already working) and forget the bridge circuit measuring capacitance value since that function is now ready available on the many dime store DVOMs these days.

So, if you have a digital meter; then you likely have all you need to measure value. I've seen a few that don't measure higher value caps though. I don't recommend the $10 Chinese standalone units on Ebay. I tried one out of dumb curiosity and the thing can read one minute and the next be erratic, which probably should be expected for the money and origin. Decent equipment (whether old or new) is very important IMHO. The poster simply wants to check a suspect cap, then he may not want to restore his test equipment. Really he would come out cheaper just tacking in another cap OR buying a decade cap substitution box is another approach. They come in different value ranges, but one must bare in mind that the sub caps may be old. I have a couple and they work close enough for troubleshooting which in the vintage realm can leave a wide tolerance for value inaccuracy. DON'T fall for what I call the Ebay Sprague Tel-o-Mike scam. They are impressive looking enough to make you think it simply must be the best thing ever. The last series (TO-6) are the ones bringing a couple hundred bucks. The prior TO-4 and 5 can be obtained much cheaper and function pretty much the same. Even they are often pricey still just because of the popularity trend that drove all the prices up in recent years.

Cheaper Knight, Eico, and Heathkit models will do anything the Capillacs will do as far as simply snuffing out bad caps. They just have basic R-C functions only and not several other functions to add to complications. I have a Sprague TO-4 that needs a little TLC to be fully functional. The bridge was really whacked, but the load test worked. I opted for a Semcore (not Sencore) which is a Philippine knock off of the Spragues but built much better.
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Old 04-05-2018, 04:58 PM
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Kamakiri Kamakiri is offline
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I *just* got in an Eico 955. Unknown, but I can try it out. PM if interested.
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Old 04-06-2018, 08:49 AM
WISCOJIM WISCOJIM is offline
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Quote:
Originally Posted by Dubis7 View Post
Hi all,

I'm planning to revisit a tape recorder repair that may be suffering from a bad capacitor of a type that doesn't usually go bad.
Much cheaper to just replace that capacitor.

.
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