Bill,
Check the values of the string of resistors in the voltage measuring path.
Those old carbon comp resistors increase in value with age. I had an old
Commander amp and that's what the problem was. I bought new resistors that
were HV rated also from Mouser. They have a page with high voltage resistors
listed. Of course, I hope that's what the problem is.
73 Hardy N7RT
----- Original Message -----
From: "BILL KENNAMER" <k5fuv@prodigy.net>
To: <amps@contesting.com>
Sent: Wednesday, August 20, 2014 4:02 PM
Subject: [Amps] MLA-2500 problem
I have what I consider to be a strange problem with my MLA 2500.
First, I should mention that it has been in storage for several years, and
it's obviously over 30 years old. It shows only 800V on the meter. My
first thought is power supply, and my second thought would be old filters.
But, in my past experiences with amp power supply failures, they are
usually accompanied by a lot of smoke and noise, along with blown fuses.
The time delay does seem to work, as near as I can tell.
Anyone have any thoughts? Also, I'm thinking that if I replace the
filters, maybe an increase from 150uF to 220uF or so might help voltage
stability. Any suggestions?
Bill K5FUV
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