Sometimes when I restore one of these AA5s, I replace the electrolytic caps and run the unit for some eight hours ( 1 day ) or so and it works fine with the wax caps in place. Sometimes when I run a unit for the same amount of time, one or more of the wax caps fails by causing distortion, flashover, etc.

The question is:

Should I ALWAYS recap no matter what, or should I do it the way I am - running the unit with the existing wax bypass and coupling caps in place, checking performance and THEN recapping as necessary?

Gentlemen, all your thoughts....

Thanks
Lou

All I can tell you is what I do....

Replace all electrolytics and all paper/wax caps.
I leave the low value domino caps alone unless one of them interferes with proper operation of the circuit.

To each his own.

Dennis

I replace the filter capacitors and all of the paper/wax capacitors. I test the Mica capacitors with a EICO 950B capacitance tester for value and rated voltage.

When i repair a 70 or so year old radio for a customer i expect it to last for another 70 years.

After a repair my long term testing of the radio can be fron a week to a month of continous operation.

I would not trust old capacitors to last 70 more years without failure, the capacitors today are fairly inexpensive if bought in volume.

Best of luck,

Mitch

The temptation is that after you get the radio running by replacing the electrolytics, you think you are done. Actually some of the radios I have fixed without recapping work well, even after some 8 hrs of playing. However, I guess when you are selling them to someone else, you have to be more thorough and replace all the fixed caps. I have found this VERY necessary when working with TVs.

Lou

:You'll probably get a dozen different opinions on this.
::
::All I can tell you is what I do....
::
::Replace all electrolytics and all paper/wax caps.
::I leave the low value domino caps alone unless one of them interferes with proper operation of the circuit.
::
::
::To each his own.
::
::Dennis
::
:I repair old radios for customers and sell some that i have repaired from my shop in a small town in NC.
:
:I replace the filter capacitors and all of the paper/wax capacitors. I test the Mica capacitors with a EICO 950B capacitance tester for value and rated voltage.
:
:When i repair a 70 or so year old radio for a customer i expect it to last for another 70 years.
:
:After a repair my long term testing of the radio can be fron a week to a month of continous operation.
:
:I would not trust old capacitors to last 70 more years without failure, the capacitors today are fairly inexpensive if bought in volume.
:
:Best of luck,
:
:Mitch
:

All of your inputs are much appreciated!!

Lou

:Replace all wax and paper capacitors. Why not do this to insure a long lasting dependable radio.
::
:Yep it is best to replace all of the wax/paper caps. Hardly ever find one that is even close to what they are suppose to be in value. George T
:
:

::Thanks Guys
:
:All of your inputs are much appreciated!!
:
:Lou
:
::Replace all wax and paper capacitors. Why not do this to insure a long lasting dependable radio.
:::
::Yep it is best to replace all of the wax/paper caps. Hardly ever find one that is even close to what they are suppose to be in value. George T
::
::
:
:

And a handful of caps isn't going to break the bank either when you purchase a variety kit from RadioDaze or JustRadios. That's my opinion, when you are in there replacing electros, take the time and just do it right.

I started to restore a radio last night, it had a bad volume control and on/off switch, mechanically smashed in the chassis. I replaced it and one of the wax capacitors connected to it.

I powered the radio up with a isolation transformer and variac. It came to life and was playing stations for a few minutes.

Then the "BIG BANG" with alot of smoke and my variac shutting down,(safety trip) as expected.

I was gathering the replacement capacitors when this occured.

Always change them all.

Mitch

Well the proof is in the picture!! Thanks for the great pic!!

I think what I will do is any receivers I work on for MYSELF I will only recap as necessary. For those receivers that I SELL I will fully recap. If something happens to one radio at HOME - no big deal. But in a CUSTOMERS HOME, not acceptable!!

Lou

::Replace all wax and paper capacitors. Why not do this to insure a long lasting dependable radio.
:::
::
::And a handful of caps isn't going to break the bank either when you purchase a variety kit from RadioDaze or JustRadios. That's my opinion, when you are in there replacing electros, take the time and just do it right.
::
:
:I started to restore a radio last night, it had a bad volume control and on/off switch, mechanically smashed in the chassis. I replaced it and one of the wax capacitors connected to it.
:
:I powered the radio up with a isolation transformer and variac. It came to life and was playing stations for a few minutes.
:
:Then the "BIG BANG" with alot of smoke and my variac shutting down,(safety trip) as expected.
:
:I was gathering the replacement capacitors when this occured.
:
:Always change them all.
:
:Mitch
:
:
:
:
:

::Mitch:
:
:Well the proof is in the picture!! Thanks for the great pic!!
:
:I think what I will do is any receivers I work on for MYSELF I will only recap as necessary. For those receivers that I SELL I will fully recap. If something happens to one radio at HOME - no big deal. But in a CUSTOMERS HOME, not acceptable!!
:
:Lou
:
:
:::Replace all wax and paper capacitors. Why not do this to insure a long lasting dependable radio.
::::
:::
:::And a handful of caps isn't going to break the bank either when you purchase a variety kit from RadioDaze or JustRadios. That's my opinion, when you are in there replacing electros, take the time and just do it right.
:::
::
::I started to restore a radio last night, it had a bad volume control and on/off switch, mechanically smashed in the chassis. I replaced it and one of the wax capacitors connected to it.
::
::I powered the radio up with a isolation transformer and variac. It came to life and was playing stations for a few minutes.
::
::Then the "BIG BANG" with alot of smoke and my variac shutting down,(safety trip) as expected.
::
::I was gathering the replacement capacitors when this occured.
::
::Always change them all.
::
::Mitch
::
::
::
::
::
:
:

Lou, why would you not place the same importance on your own radios vs a customers radio?

Also, if I was replacing a cap on a tube terminal I would also test and replace a resistor (if necessary)on that same terminal at the same time as the cap. It would cut down the work (if necessary) and cut down the additional stress on that terminal.

Vin

::Mitch:
:
:Well the proof is in the picture!! Thanks for the great pic!!
:
:I think what I will do is any receivers I work on for MYSELF I will only recap as necessary. For those receivers that I SELL I will fully recap. If something happens to one radio at HOME - no big deal. But in a CUSTOMERS HOME, not acceptable!!
:
:Lou
:
:
:::Replace all wax and paper capacitors. Why not do this to insure a long lasting dependable radio.
::::
:::
:::And a handful of caps isn't going to break the bank either when you purchase a variety kit from RadioDaze or JustRadios. That's my opinion, when you are in there replacing electros, take the time and just do it right.
:::
::
::I started to restore a radio last night, it had a bad volume control and on/off switch, mechanically smashed in the chassis. I replaced it and one of the wax capacitors connected to it.
::
::I powered the radio up with a isolation transformer and variac. It came to life and was playing stations for a few minutes.
::
::Then the "BIG BANG" with alot of smoke and my variac shutting down,(safety trip) as expected.
::
::I was gathering the replacement capacitors when this occured.
::
::Always change them all.
::
::Mitch
::
::
::
::
::
:
:

All the Best,

Bill