Replace the filter and relay PS caps plus the HV multiplier resistors.
Then you can test the amp with the tubes removed at first.
The next step is some improvements as well as seeing what hacks were
done....such as bypassing the input load resistor which is a great way to
get 1500W and a soon dead set of tubes.
Carl
KM1H
----- Original Message -----
From: "BILL KENNAMER" <k5fuv@prodigy.net>
To: <amps@contesting.com>
Sent: Wednesday, August 20, 2014 7:02 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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