I have a few restoration projects planned and would like to know if it would be better to do a complete recap or just replace the bad capacitors in a radio? How will either choice affect the value of the set? These are radios that I plan on using regularly.

Unless they are rare, recapping won't effect value. What radios are you considering recapping? Mica capacitors should not be replaced, normally only the electrolytic and paper caps.

Richard

:Unless they are rare, recapping won't effect value. What radios are you considering recapping? Mica capacitors should not be replaced, normally only the electrolytic and paper caps.
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:Richard

:Unless they are rare, recapping won't effect value. What radios are you considering recapping? Mica capacitors should not be replaced, normally only the electrolytic and paper caps.
:
:Richard
The radios are a Truetone d2923 AM wood radio, a Philco 49-909-121 wood radio and a GE F-70 3 band wood radio. I especially like the GE F-70.

We are finding more bad mica's, and some of what you may think are mica's are paper. Best to replace them all and be done with it.

I heard about some capacitors that look like mica actually being paper. I guess your information confirms it. Thanks for the heads up on that.

Looked at a photo and schematic on the GE F-70. That's a really nice old radio. Good Luck! Richard

Thanks. I will be ordering parts this weekend so most likely will start restoring it in two or three weeks. The radio was well cared for so it should look nice when it is done. Thanks again for your help.
Phil Ragusa

Here's the scoop. It is wise to replace all condensers in order to establish reliability in your radio. The yellow metalized film caps often fit nicely within the old cardboard tubes which housed the original condensers.

Mica condensers can sometimes be paper condensers. This is why they should not be overlooked, though if they test out with no leakage, then they are likely fine. On occasion one will arc even though it tests out fine on your meter. Sometimes you can crack these units open and stash small modern ceramic disc units inside.

I, personally, am disgusted when I find an old radio which is littered with new components, with no attempt at making the radio look somewhat original. I steer clear of these radios unless they are otherwise remarkable in condition and styling. It takes only a little extra time to stuff new caps in the old cardboard tubes. If your set is post-1950, however, simply replacing the old components with new ones doesn't make much difference.

A condenser is considered bad when it has any leakage at all. That is, if it has even 10 or 15 million ohms leakage, it is bad. When you check a condenser with your meter, if the needle swings up at all, it should go back exactly to where it started (infinity). If it lingers even slightly higher (a thousandth of an inch), the condenser is unacceptable. Electrolytics can have a bit of leakage. 10 meg is quite fine. Anything less than 1 meg is unacceptable, though such leakage may simply be due to the condenser not being in use for some time. If the leakage is much below this, the condenser should be thrown away, but if it is at around 1 meg or higher, it may be rejuvenated with a power supply which supplies a voltage just under the maximum rated voltage of the electrolytic. Charge the electrolytic through a 5K resistor for 20 minutes. Discharge the condenser with a 20K resistor until no voltage remains. Test the condenser. Such practice is somewhat a waste of time, though, as your radio's power supply is expensive. It is better not to take risk with old electrolytics. If you wish, some electrolytics may be cut open so that new units may be placed inside. It is easier and quite satisfactory to disconnect the original units and just stash new units under the chassis. With the original units still on the chassis, having new units under the chassis is acceptable asthetically.

Thomas