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Re: [Amps] ALPHAs and momentary power outages

To: "'Jim Brown'" <>, <>
Subject: Re: [Amps] ALPHAs and momentary power outages
From: "Dick Green WC1M" <>
Date: Wed, 18 Jul 2007 11:27:10 -0400
List-post: <>
> Sometimes simple and brute force is better. Earlier in this thread, it
> was suggested that the timer was microprocessor based, not in discrete
> circuitry, and was not easy to reprogram. Some things are easier to do
outside the
> box.

I'm glad someone was paying attention. It would be hard to reprogram the
microprocessor, but it would be easy to patch the timer value on the fly, as
needed. You just have to get the address(s) and meaning of the value(s) from

Some who may not have been paying attention suggested "cutting out" the
Alpha timer circuit. For grins, I took a quick look at the schematic to see
if that can be done. There's a "STEPSRT" line running from the
microprocessor board to the AC Module. It's connected to a relay coil that
connects the other half of the 220VAC line to the main transformer. I
haven't looked inside the amp, but it's probably not difficult to cut that
line and substitute a timer circuit like the one W8JI described.
Unfortunately, the microprocessor would still think it's in warmup mode and
probably wouldn't function correctly. I believe the Alpha code is
single-threaded, so it probably waits in a loop for the timer to complete or
implements the timer by looping.

I still think the best, cheapest and simplest course of action is to ask
Alpha for the timer warmup address.

73, Dick WC1M

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