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[AMPS] Blown TL922A... What to do?

To: <amps@contesting.com>
Subject: [AMPS] Blown TL922A... What to do?
From: 2@vc.net (measures)
Date: Wed, 13 Sep 2000 13:43:21 -0700
>
>> This sort of action smacks of what happened to Walt Maxwell's
>> material and his reputation as a result of an approach to the
>> ARRL by a famous former Collins Radio amplifier engineer.
>
>That incident was another terrible shame.  I believe the issue presented was
>whether a conjugate match exists at the output of a vacuum tube-based
>amplifier at a condition of maximum power transfer.  After the Collins
>engineer wrote the article in QST, I went back to Walt's book,
>"Reflections," in an effort to determine the root of the inconsistency.
>Walt placed a caveat in his text which was consistent with the Collins
>engineer's opinion on the relationship of the conjugate matching theorem and
>tube-based amplifiers.  However, one had to dig to find it.
>
>Two problems as I see it: the man never completely read or absorbed Walt's
>material, and secondly, Walt could have presented the material a bit more
>clearly but in all fairness to Walt, I believe he was trying to deliver the
>concept to an "amateur" audience.  Nevertheless, Walt's thrust with
>conjugate matching in his book emphasized the need to cancel reactances in
>the *antenna system* (transmission line + antenna) in order to effectuate
>maximum power transfer between the source and its load.  Somehow, the notion
>of conjugate matching to achieve maximum output power reached back to the
>internal mechanics of the amplifier.  For the intent, purpose and level of
>understanding Walt was trying to convey to his readers, any reference to the
>amplifier mechanics was probably unnecessary.  As a result, Walt's text was
>taken out of context and he is no longer an authoritative source in the eyes
>of the League's technical staff.
>
>I'd bet a paycheck that if George Grammer was living and back on the
>League's staff at the time of either publication, he would have never
>allowed these incidents to occur.
>
quite probable, Paul.  Curiously, QST currently has no Technical Editor.  

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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