I would just get the new capacitors. I once hooked up an old Johnson
Thunderbolt and tried to get it to power up. I let everything percolate
for a while and then fired up the high voltage. I wound up vaporizing
the fuse elements and flash depositing them on the glass tubes of the
fuses. Then, I replaced all the caps with brand new ones. Luckily
nothing else blew up.
Steve WA9JML
Ken Brown wrote:
Anyone have a quick link or a reference to the right way to bring up an
old amp power supply? I have a variac for both 120 and 220, and I got
an old friend's Drake L4B, not used for at least 10 years (maybe more)
and nothing was apparently wrong when it was stored (he was looking for
chimney's of some sort). I'd like to bring the power supply up so that
the electrolytic caps will work once again.
In theory bring it up slowly current limited to reform the capacitors.
But in my experience more have failed immediately than I've successfully
reformed. New electrolytics are more sure to work. More than one failed
electrolytic for me has filled the chassis with shredded foil and
electrolyte filled crepe paper. A really tough mess to clean up. Old
electrolytics don't get that chance anymore.
Not used for at least 10 years, and the capacitors are certainly a lot
older than that. When you compare the cost and labor of buying new ones
and putting them in first, versus the cost and labor of cleaning up the
mess of exploded old capacitors AND buying new ones and putting them in,
I think the best choice is just to buy new ones and put them in first.
I wonder if you could fit an oil filled capacitor of similar capacitance
value and voltage rating in the same space, instead of using electrolytics?
DE N6KB
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