k4kyv at charter.net
Fri Feb 2 20:50:56 EST 2007
The leakage should be very high, in the tens of megohms.
But if it isn't, don't throw the transformer out just yet. Let it sit in a
dry place with low humidity for a few weeks, then check it again. You may
be surprised that the leakage resistance has gone much higher. If it is not
yet high enough to be satisfactory, let it sit a while longer.
I recall Mike, N14N (now W4AAE), found a 1940's vintage UTC modulation
transformer that had been stored in an unheated shed since sometime in the
1940's. It tested very poorly, with a tremendous amount of leakage. After
a few months in his dry shack, the leakage was undetectable with his megger.
He later used it with a pair of 833A's to modulate another pair of 833A's,
and it worked just fine.
I suspect that if he had used it in that modulator before letting it dry
out, it would have failed in short order.
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