Im aware of that part Paul. I was referring to a fix that allowed the EBS to
still be used. Its been a long time and I dont remember the details but it
didnt come from Alpha. It might have been in HRM as that was about the only
technical mag at the time.
Carl
KM1H
----- Original Message -----
From: "Paul Christensen" <w9ac@arrl.net>
To: <K8MLM@aol.com>; <km1h@jeremy.mv.com>; <audioguy@charter.net>
Cc: <amps@contesting.com>
Sent: Wednesday, December 30, 2009 7:58 AM
Subject: Re: [Amps] Alpha 78 Problem
>> When the 77 was still in regular use it was easy to spot one by the
>> splatter
>> caused by the electronic bias spike. There has been a lot written about
>> a
>> fix.
>
> I spoke with Ray Heaton about this back when I purchased my first 77Dx.
> On the Dx/Sx models, the EBS can be defeated by adjusting one
> potentiometer on the bias board. Plate idling current can be adjusted to
> reasonable levels and the added heat produced when the key line is pulled
> low is never a problem.
>
> By contrast, my Alpha 70V uses a fixed EBS system and when signal strength
> on the Rx end is very strong, artifacts from the EBS can certainly be
> heard. I have two different modifications for this but decided to leave
> the original EBS intact, at least for now.
>
> Paul, W9AC
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