I believe the greatest issue with maintaining the 87A further down the road
are the hard programmed PALs (16 and 20) that as I understand cannot be read
or cloned. Anyone have any success?
73 Jerry
NY2KW
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Paul
Christensen
Sent: Friday, October 07, 2016 11:58 AM
To: amps@contesting.com
Subject: Re: [Amps] Alpha 87A Alpha Max Upgrade
Jim,
Yes, you can upgrade it without difficulty once you have the
AlphaMax/AlphaRemote chips. I've upgraded several 87A amps over the years.
Maybe check with Mike Dishop or Glenn Pladsen concerning chip availability.
Come to think of it, it might not be a bad idea for those of us who love the
87A to stock up on those chips as well as RAM/ROM. Most all other parts
used in the 87A can be sourced from other vendors, including compatible
substitutes.
If you decide to go through with the amp purchase, also consider bumping up
the Rx diode bias voltage by adding to the Zener string. As I recall,
there's on-line information for the mod and it would bring the amp up to
late-production performance by adding even more SWR protection to the Rx PIN
diodes. I firmly believe the bad-rap given to the 87A/89 PIN design is
attributed to Rx bias. If my information is correct, Alpha did not achieve
the last level of bias improvement until about 2000. That's a full decade
of 87A/89 production that may benefit from a bias circuit upgrade.
Paul, W9AC
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, October 4, 2016 2:08 PM
To: Amps Amps <amps@contesting.com>
Subject: [Amps] Alpha 87A Alpha Max Upgrade
I'm considering the purchase of an 87A that shipped from the factory in
1993. I suspect that it does not have Alpha Max firmware. Some questions.
1) How big a deal is this?
2) I know that chips must be changed and that firmware must be loaded.
Are these generally available?
3) Any known issues with doing it now?
Thanks and 73, Jim K9YC
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