Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: catnine on July 13, 2011, 05:42:47 pm

Title: I have to ask .
Post by: catnine on July 13, 2011, 05:42:47 pm: Do most builders here own a capaciter meter . I always intended to get one but never did . I just trust the caps I get new are within spec. I have all sorts of DVOM's and analog volt/ohm meters and everything else .

I am ready to be :cussing:
Title: Re: I have to ask .
Post by: phsyconoodler on July 13, 2011, 06:09:28 pm: If you have a DVOM you already have a capacitance tester.They have that feature on most of them if you know how to use it.

I haven't bothered with testing caps unless I have a problem or one with the lettering rubbed off.Been lucky so far.
Title: Re: I have to ask .
Post by: catnine on July 13, 2011, 07:00:21 pm: Quote from: phsyconoodler on July 13, 2011, 06:09:28 pm
If you have a DVOM you already have a capacitance tester.They have that feature on most of them if you know how to use it.

I haven't bothered with testing caps unless I have a problem or one with the lettering rubbed off.Been lucky so far.

The newest DVOM I have is a greenlee DM-200 , it does not feature a cap tester, it does have auto range or manual select . The other one is an older Micronta 185-A DVOM it is manual select yet if I read a resister or voltage it reads exactly the same as the Greenlee, and a even older Micronta analog clam shell that I don't use much but none have cap reading capability.
Title: Re: I have to ask .
Post by: The_Gaz on July 13, 2011, 07:36:13 pm: I have part S-Z150 from Antique Electronics Supply ($40). I has a .1pf to 20,000 uf range, two slots so you can quickly stick the two leads of the cap straight into the meter, and a knob to "zero-out" the internal capacitance of the meter or the test leads when measuring small values. Many new DMMs have cap test built in, but sometimes the ranges don't work well for gtr amps.
Title: Re: I have to ask .
Post by: tubeswell on July 13, 2011, 07:50:23 pm: One of my multimeters has got a capacitance measuring function, which I use now and again out of curiosity. However, with geetar amps, the marking stamped on the cap is near enough.
Title: Re: I have to ask .
Post by: stingray_65 on July 13, 2011, 10:48:14 pm: I have to give a +1 to buying a nice Fluke (redundant?)

I do own a few Flukes (none with capacitance capability)

I bought a Harbor frieght meter just for reading caps.

I find it Most useful for checking caps labeled like 106k

only reads to 2 uf so basicallt electrolytics get read Over Scale

Best use is for silver Micas where I cant read the small print at all

Yes I use mine, mostly out of laziness and poor eye sight.
Title: Re: I have to ask .
Post by: jojokeo on July 14, 2011, 01:05:54 am: I've got three types w/ several that read basic measurements and these are handy when you want to be sure what you're using either to double check or verify you have the right one. The smaller pF range types can vary more than you think. A second one is an ESR-type tester just for measuring electrolytics and can also be used in or out of circuit which tests using a high frequency on the cap, and the third is one that checks for passing DC that's a little primitive but hey you can build it yourself for cheap so beggers can't be choosers. :) This puts a DC charge on the cap using a SPDT or DPDT w/ one way being a momentary but you can use a simple SPST on/off/on if you want. Anyway, press to charge the cap and release or switch to get a DC reading w/ your meter (or flip it the other way) middle position is off. This doesn't test w/ high voltage but you're supposed to scale the 9v to get an idea what you've got. It can check all types of caps. With e-lytics you will get some DC and this is what you're suppposed to scale and get the feel for, the smaller ODs, Mallorys, ceramics, etc. shouldn't pass any DC. With practice you can get fairly good w/ it and if you use recycled parts it may be worth it and/or simply fun for a quick project?