I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.

Dave

:I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
:
:Dave
:

I learn something new everyday, thanks for the info.

Charlie

Dave

I sure agree with you on electrolytic caps. Change them unless you know they have been replaced within the past 20 years. It's not worth using NOS electrolytic caps. Always buy new manufacturer.

Mica caps can go bad and cause crackling. Most will be ok.

Now about using a VOM to check paper caps.. You are correct a VOM doesn't test caps at their rated voltage. If a person has a meter like Triplett 630, which uses a 30 volt battery, on the highest resistance scale it will sort out leaky caps.

Norm

::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
::
::Dave
::
:
:I learn something new everyday, thanks for the info.
:
:Charlie

:I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this.

Absolutely.

I use an Eico 950B modified to go beyond 600V. Quite useful. I also made a little ESR meter which is great for testing electros. Simple thing to build. You possibly can't test any cap with an ohmmeter other than looking for a shorted one. The Sprague is a fine unit, but one can find an Eico on eBay for maybe 20$ or less. A must have (either one). A digital cap meter is only good to test known good caps for their values or for matching.

Z-

::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this.
:
:Absolutely.
:
:I use an Eico 950B modified to go beyond 600V. Quite useful. I also made a little ESR meter which is great for testing electros. Simple thing to build. You possibly can't test any cap with an ohmmeter other than looking for a shorted one. The Sprague is a fine unit, but one can find an Eico on eBay for maybe 20$ or less. A must have (either one). A digital cap meter is only good to test known good caps for their values or for matching.
:
:Z-

Timely discussion. I've been planning to present my situation on a Stromberg-Carlson Console Radio Phonograph from 1957 Model FR503/4. I picked it up at no cost. I was told it worked and "momma" played it up til her death. I always say to folks I don't care working or not you don't have to plug in the set for me. At home straying from my normal procedure of first checking transformer outputs and start on recap job I decided to start it up on variac. Allowing little time I run it on up to 120 and play, did it play. I waited. No distortion and absolutely no hum. I mean no hum, buzz, squeal, motorboating, etc. All this while on the tailgate of my truck. I let it play on and went about picking up sticks and trash from the yard. After about an hour I took it in the shed, put the chassis on the bench, played it some more while I searched for a EM85 tuning indicator. Well I didn't find one yet. Next day I replaced the four wax paper caps one at a time just to see if I could hear a difference. I couldn't. I looked at that 20-20-40-25 and decided to leave it be. Most always it's a given for me to replace the electrolytics, no testing.

I've encountered this many times before but mainly with mid 60's onward in which I have more confidence in the caps of that time. This radio plays so well. I have only tested the 5Y3. My FADA 250G played for a number of years with only one wax paper cap replaced. Nothing wrong but a few years ago I got nervy about it and recapped it and replaced resistors. It plays great as before but I wished I had let it along. You know I feel I interrupted it's normal life cycle. It's not my oldest radio but it's the one I've had the longest, about 25 years.

Bill VA

I have quite a few radios, too, that play well with all of their original components. I have one Zenith portable in which I replaced all of the paper condensers because they were leaky, but left the electrolytics alone. It's from 1940. I've had it since about 1992, and play it a TON. It is absolutely hum free to this day. I always test all of the components before powering up a set, but if they all test perfect, I give it a try as-is. Good luck convincing everyone, though. ...And, regarding safety with micas, if the unit really is mica, it is no less safe than a brand new mica, since they're made with the same materials. I think that it is a very good idea to replace paper condensers if you're not going to keep a set, but micas, if they really are micas, should probably be left alone.

T.

To each his own... but..
I feel that.. if I've taken all the effort to pull a chassis and clean it up and align it all... why would I want to test out an old capacitor in the futile hopes of leaving it in there a while longer... only for it to fail sometime later?
(unless the old-looking cap is what you must have)
For the silly few cents or possibly a couple bucks I can't see fiddling around trying to squeeze a little more time out of a 60 year old potentially flakey component? C'mon guys... lol
I'd rather know for sure that when I close up the radio... I (or my customer)won't ever have to wonder if a furure problem is caused by that old time-looking piece-o-crap capacitor finally biting the dust or is beginning to act intermittently.
How cheap and foolish I say... lol

And as I said .. maybe only to preserve the "original look.. maybe..
but even then ....you could restuff with new!!
... if you like/enjoy spending/wasitng time... at least restuff and know the component will hold up??

Think about spending the money buying a capacitor testor... lol...
Then.. unsoldering it... testing it.. and putting it back!
Then counting the days or months even maybe years while the ticking time-bomb finally quits.
How silly. No?

If I un-solder it.. and replace it I'm done... all in less time than it takes to test it.
And.. well yes... I did spend like maybe 37 cents maybe...
Well spent I say.

Peter,

Got to thinking. I suppose if all the communications equipment I have repaired over the years had to be kept looking like it came from the factory (underneath the chassis), I believe I would still have a backlog of 50s and 60s equipment (especially if I had to restuff a cap). A repair part ordered from the manufacturer (I generally ordered repair parts from them) quite often did not look the same as the original one. In some cases the replacement cap may be changed from a paper type to a ceramic type of the same value.

Radiodoc

:To each his own... but..
:I feel that.. if I've taken all the effort to pull a chassis and clean it up and align it all... why would I want to test out an old capacitor in the futile hopes of leaving it in there a while longer... only for it to fail sometime later?
:(unless the old-looking cap is what you must have)
:For the silly few cents or possibly a couple bucks I can't see fiddling around trying to squeeze a little more time out of a 60 year old potentially flakey component? C'mon guys... lol
:I'd rather know for sure that when I close up the radio... I (or my customer)won't ever have to wonder if a furure problem is caused by that old time-looking piece-o-crap capacitor finally biting the dust or is beginning to act intermittently.
:How cheap and foolish I say... lol
:
:And as I said .. maybe only to preserve the "original look.. maybe..
: but even then ....you could restuff with new!!
:... if you like/enjoy spending/wasitng time... at least restuff and know the component will hold up??
:
:Think about spending the money buying a capacitor testor... lol...
:Then.. unsoldering it... testing it.. and putting it back!
:Then counting the days or months even maybe years while the ticking time-bomb finally quits.
:How silly. No?
:
:If I un-solder it.. and replace it I'm done... all in less time than it takes to test it.
:And.. well yes... I did spend like maybe 37 cents maybe...
:Well spent I say.
:

RadioDoc:

.. huh?
... lol.. sorry I appologize Radiodoc.. but either I'm unable to undersand your meaning ... lol....
...or I'm just lost... sorry but I don't know what you said or what you meant....lol.
am I drunk or high in electrons.. lol

Peter,

Just ramblings of an old codger.

Radiodoc

:RadioDoc:
:
:.. huh?
:... lol.. sorry I appologize Radiodoc.. but either I'm unable to undersand your meaning ... lol....
:...or I'm just lost... sorry but I don't know what you said or what you meant....lol.
:am I drunk or high in electrons.. lol

Hey.. I'm an older codger too.. oldre codger probably than you "old codger" so don't ya think I'd get it?..
guess there's no hope for codger^nth degree

Peter,

You very well may be. But I bet either of us may be hard pressed to be as old as a magazine I received over the weekend I have started reading. An October 1927 edition of Radio News. A friend (a radio and TV tech for many, many years) was doing some early spring cleaning, found it and asked if I was interested. Otherwise he was going to throw it away. It is a bit tattered, but quite readable and has several diagrams for radios in it.

Radiodoc

:Hey.. I'm an older codger too.. oldre codger probably than you "old codger" so don't ya think I'd get it?..
:guess there's no hope for codger^nth degree

Doc:
How come the older we get the more old stuff we like (but women should be younger...lol)

Well here's a little older magazine that originally only cost 35 cents and I just paid $35 for it... just because I love the cover... lol
http://www.pbpix.com/radio/RadioBroadcast-1926.jpg

And in fact I stole the cover image for my radio repair webpage opening page.
www.pbpix.com/radio

Hey.. I'm an older codger too.. older codger probably than you "old codger" so don't ya think I'd get it?..
guess there's no hope for codger^nth degree

:I searched for a EM85 tuning indicator. Well I didn't find one yet.

I just picked up my French radio at a buddy's and the EM85 was, you guessed it, dead. So he simply replaced it with a Russian EM80. He told me the EM80 will work in 95% of the case (only in rare occasion where the triode is also used as an amp.). It worked beautifully in mine after swapping 4 wires. A simple task to do at the eye tube socket. The Russian eye tubes are _very_ bright and also cost a lot less than any other brand. They are every bit as good as far as I'm concerned. BTW, I also learn tonight that an EM85 can cost up to 40$! That makes the option of using an EM80 even better.

Z-

Next day I replaced the four wax paper caps one at a time just to see if I could hear a difference. I couldn't. I looked at that 20-20-40-25 and decided to leave it be. Most always it's a given for me to replace the electrolytics, no testing.
:
:I've encountered this many times before but mainly with mid 60's onward in which I have more confidence in the caps of that time. This radio plays so well. I have only tested the 5Y3. My FADA 250G played for a number of years with only one wax paper cap replaced. Nothing wrong but a few years ago I got nervy about it and recapped it and replaced resistors. It plays great as before but I wished I had let it along. You know I feel I interrupted it's normal life cycle. It's not my oldest radio but it's the one I've had the longest, about 25 years.
:
:Bill VA

I've ordered a couple of EM80's. My EM85 has some green but does test bad. I wonder if there's something one can do to the plate voltage that might help.

Bill VA

::I searched for a EM85 tuning indicator. Well I didn't find one yet.
:
:
:I just picked up my French radio at a buddy's and the EM85 was, you guessed it, dead. So he simply replaced it with a Russian EM80. He told me the EM80 will work in 95% of the case (only in rare occasion where the triode is also used as an amp.). It worked beautifully in mine after swapping 4 wires. A simple task to do at the eye tube socket. The Russian eye tubes are _very_ bright and also cost a lot less than any other brand. They are every bit as good as far as I'm concerned. BTW, I also learn tonight that an EM85 can cost up to 40$! That makes the option of using an EM80 even better.
:
:Z-
:
:
:
:
:
:Next day I replaced the four wax paper caps one at a time just to see if I could hear a difference. I couldn't. I looked at that 20-20-40-25 and decided to leave it be. Most always it's a given for me to replace the electrolytics, no testing.
::
::I've encountered this many times before but mainly with mid 60's onward in which I have more confidence in the caps of that time. This radio plays so well. I have only tested the 5Y3. My FADA 250G played for a number of years with only one wax paper cap replaced. Nothing wrong but a few years ago I got nervy about it and recapped it and replaced resistors. It plays great as before but I wished I had let it along. You know I feel I interrupted it's normal life cycle. It's not my oldest radio but it's the one I've had the longest, about 25 years.
::
::Bill VA

:I've ordered a couple of EM80's. My EM85 has some green but does test bad. I wonder if there's something one can do to the plate voltage that might help.

If you look carefully to the target you will see grey darken areas. These are worn phospor. Nothing can be done about it other than replacing with a new eye tube.

Z-

ESR will be a main culprit in power supply and audio coupling problems. I use a couple of different testers on my bench (Capacitor Wizard and CapAnalyzer 88A) which will find the bad ones instantly. Forget about unsoldering and ohmmeter testing each suspected cap. You're wasting your time, and can't check ESR that way anyhow. Power down the unit and check all the caps in a few minutes.

:I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
:
:Dave
:

Hi All,
I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.

Best Regards,

Bill Grimm

::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
::
::Dave
::
:
:Hi All,
: I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.
:
:Best Regards,
:
:Bill Grimm

Read your article and it should remove any doubt that anyone has about the wisdom of replacing these capacitors. Excellent- everyone should take the time to read it.

:::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
:::
:::Dave
:::
::
::Hi All,
:: I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.
::
::Best Regards,
::
::Bill Grimm
:
:Read your article and it should remove any doubt that anyone has about the wisdom of replacing these capacitors. Excellent- everyone should take the time to read it.

Thank you.

Bill

Bill,
That ebay page does not work for me, any suggestions?

marv

::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
::
::Dave
::
:
:Hi All,
: I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.
:
:Best Regards,
:
:Bill Grimm

Marv,

Make sure if you copy and paste the link into your browser you do not copy the (.) period at the end of it or it will not work. I missed the period the first time.

Radiodoc

:Bill,
:That ebay page does not work for me, any suggestions?
:
:marv
:
:::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
:::
:::Dave
:::
::
::Hi All,
:: I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.
::
::Best Regards,
::
::Bill Grimm

Doc,
Thanks, I didn't catch the (.), but it worked this time

marv

:Marv,
:
:Make sure if you copy and paste the link into your browser you do not copy the (.) period at the end of it or it will not work. I missed the period the first time.
:
:Radiodoc
:
:
::Bill,
::That ebay page does not work for me, any suggestions?
::
::marv
::
::::I have seen suggested many times on this forum to use an ohmmeter to test capacitors. Capacitors should always be tested at their operating voltage, a ohmmeter cannot do this. I use a Sprague TO-6 but any of the Heathkits, Eico, or other inexpensive units will work fine. The newer digital capacitor tester will not work, they do not supply the required voltage. Usually paper caps should always be replaced, they deteriorate from the inside, if the are not bad when you test them they soon will be. Mica caps will usually be good, but should always be tested at rated voltage. Due to the amount of bad mica capacitors I have been finding I now replace the mica's in anything I will be restoring for resale. I always replace the electrolytics, they may test good and you may be able to reform them but I toss them in the garbage can, for a couple of bucks it is just not worth taking a chance on them. These are my suggestions, many of you may have old radios that are working fine with the old capacitors and electrolytics, I do too, but these are for my own use and I would never sell them in this unsafe condition.
::::
::::Dave
::::
:::
:::Hi All,
::: I have written a guide on why paper wax capacitors need to be replaced for eBay. It ia almost impossible to find on eBay now since they messed up the guides section. The link is http://reviews.ebay.com/Paper-wax-capacitors-why-they-need-to-be-replaced_W0QQugidZ10000000001662924.
:::
:::Best Regards,
:::
:::Bill Grimm