I have occasionally had to repair astron supplies. One particular time
comes to mind. It was the day before my 60th Birthday and I was living in
Las Vegas at the time. A good friend of mine, Fred, K9GAJ, had lived in
Vegas for several years and we enjoyed each other's company helping each
other with repairs, antennas and so forth. Unfortunately for me, he had
retired and moved to New Mexico a couple years before this incident. We
had a near lightning strike and my 35 amp astron died. I did have a
spair, but kept grumbling, "I wish Fred was here, he'd help me fix this
thing." I'm a good trouble shooter, but not good at soldering on pc
boards.
The next day was my 60th birthday and Libbie told me she might be late
from work as she had a meeting. I never gave it a thought, although I
should have, she never stayed late. Anyhow, she came home at normal time.
A couple minutes later, there was a knock at the door and I figured u p s
or some body. I opened the door and Fred said "happy birthday." I just
stood there. Finally Libbie asked me if I was going to let him in. One
heck of a surprise for my birthday which Libbie had put together. All the
time I was grumbling about Fred not being there any more, she just smiled
as she knew he'd be at my door the next day. Hard to believe she's been
gone 5 years this December. She was always doing cool stuff like that,
which is why I miss her so much. Well, we began working on the supply and
kept running in circles. Turned out to be a simple fix once we found it.
We quickly determined the driver transister was bad. We replaced that,
and still no output. There is a series resister from the emiter of the
driver, a ten ohm as I recall, to the base of the pass transisters. Fred
misread it as a thousand ohms and oddly enough, that is what it checked
with an ohm meter. I should have caught on that that was way to high a
value for where it was in the circuit. Once we replaced it with a ten
ohm, the supply was back to normal. We both should have caught that one
much soonner than we did. He kept misreading the colors and I kept
thinking 1 k was correct.
Those supplies are fairly trouble free, but lightning or a power lline
spike can get the 723 or a transister. If I remember right, the driver
was bad, but we totally kept overlooking that pesky resister.
73
Butch
WA0VJR
Node 3148
Wallace, ks.
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