The Astron RS-35s made before about 2001 did not have the negative post
grounded to the chassis of the supply. This allowed RF to enter through
the negative post and be fed right into the regulator. Astron
recommended measuring resistance from negative post to chassis and if
not a dead short, make it so. I did it by removing the insulators from
around the post, scraping a bit of paint and replacing those insulators
with lockwashers.
If I can find my correspondence with them I'll post it here.
73, Mike N4NT
----- Original Message -----
From: "Kim Elmore" <cw_de_n5op@sbcglobal.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Sunday, November 05, 2006 3:10 PM
Subject: Re: [TenTec] Astron and TenTec rigs (Paragon)
| I've had an Astron power supply for years, marketed under the name
| "Westcom." It's an RS-35A. At one time, all my equipment was close to
| my tower, which I shunt-fed for 160 m and when I used 160 m, the
| power supply had all sorts of problems. I removed the original
| regulator board and replaced it with an "RFI-proof" regulator out of
| the ARRL Handbook. The PC board is available from FAR circuits (I
| doubt that it's still available as this was a long time ago). After
| doing that, I never had another problem even at high power (which was
| only about 700 W). I concluded that the regulator board was simply
| prone to RFI and I'd guess that this is the problem you're
experiencing.
|
| Unfortunately, you'll probably have to experiment quite a bit to find
the fix.
|
| Kim Elmore, N5OP
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