There are some reforming capacitors instructions on the web. You apply a
fraction of the voltage for a few minutes, then ramp up another fraction,
and so on. You might even measure the capacitor leakage current. There are
standard values of leakage for good electrolytics and if you do not see the
current reduce during reforming, consider the capacitor history.
However, consider this: Most aluminum oxide electrolytic capacitors have
a 10 year life at best. You may better use your time, and place less risk
on the rig, to simply replace all the electrolytics before you try the rig.
Modern ones are smaller, and are not all that expensive for the peace of
mind of using fresh ones. Don't assume new old stock electrolytics are
good. I once tested all I had of one value, and none took a charge after
20 years.
You can find data sheets on the web that speak to the expected lifetimes of
electrolytics.
If you want to try reforming, Google, "reforming electrolytic capacitors" in
quotes like this. However, what might happen is you get them reformed for a
few weeks of use, and then they have higher hum and ripple and heat up and
fail catastrophically later on. If a rig has been used for many years, you
can't predict any success in getting it to power up normally.
-Stuart
K5KVH
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