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[AMPS] drive derived screen potential

To: <amps@contesting.com>
Subject: [AMPS] drive derived screen potential
From: measures@vcnet.com (measures)
Date: Sun, 19 Dec 1999 09:55:29 -0700
>
>Hi Skipp:
>
>There are perhaps 2 other reasons to use a circuit which derives screen
>voltage from the drive.  The first is that it reduces dissipation in
>proportion to the speech, so that it is zero while the operator is not
>talking - thus saving up to 750 watts every time the operator shuts his
>mouth.  The second is that is simply something different, allowing amateurs
>like to experiment.
>
>The effect of a circuit using a screen voltage derived from drive may be
>that of a volume expander.  Such devices have been used in audio circuits
>for years.  The concern is that such an operation might cause distortion
>leading to unfriendly attacks by neighboring hams.  Claims vary widely about
>the results.  G2DAF developed one circuit using that scheme. And, I am
>advised that he used a spectrum analyzer to analyze his results.  Les
>Earnshaw, ZL1AAX, developed a similar circuit.  Others have also explored
>the circuitry.  The pioneering that Les has done into electronics would give
>his circuitry a great deal of credibility - at least one which I would not
>question without doing a lot of investigation.  He designed the Atlas series
>of transceivers, developed a number of circuits for military use and more
>recently started Kachina.  As I recall from my reading many years ago, he
>was quite impressed with his development of this circuitry.
>
?  [chortle].  On the alt.religion.mormon Newsgroup, a participant who 
had claimed that he is pretty smart later stated that he "laid waist" to 
the opposing position.  

>........ The good news is that
>if you build an rf amplifier that distorts, you do not have to listen to the
>distortion.
>
?  [guffaw]

cheers, Colin

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


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