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Date: Mon, 02 Aug 1999 15:55:31 +0100
To: rsgb_lf_group@blacksheep.org
From: "Simon Lloyd-Hughes" <simon.lloyd-hughes@rd.bbc.co.uk>
Subject: Re: LF: Re: Class E RF amplifiers
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There was a Class E 7MHz amplifier design in QST in early 1997.  It was in
two parts with practical design information. 


At 11:11 02/08/99 +0200, you wrote:
>>>From PA0SE to All
>
>Alan Melia wrote:
>
>
>>Hi all, I dug out a copy of an article by Nathan Sokal (Pres. of Design
>>Automation) that was published in Design Electronics on 20 Sept 1977 titled
>>"Class E can boost efficiency".
>>This turns out to be a very practical article with simple design formulae,
>>and a 'build it and play' circuit with example scope traces of current and
>>voltage waveforms. The test circuit is to run at 10 MHz but the detail
>looks
>>eminently suited to 136kHz. Efficiencies of 82 to 95% are quoted for some
>>very ordinary transistors and FETs. There is no formula given for the RF
>>Choke but I think that can be scaled from the 10MHz value.
>>
>>I know some have Class E stages already, but this may be a help to others
>to
>>get the parameters right. It looks as though I no longer have the original
>>magazine, but it looks as though the copy I have will re-copy. Anyone
>>interested.......if there are too many, can anyone offer to scan it in?
>>Though there may be a copyright problem there even on a 22 year old
>article.
>>I have a sneaking suspicion the gentleman is a Ham, though he didn't admit
>>to it in the corresponece I had with him in the late 70s or in the article.
>>I wonder if Andre knows?
>>In the meantime I'm willing to snail-mail copies (until the Bank Manager
>>objects)
>
>
>
>Useful information on class D, E and F amplifiers with references to the
>original articles can also be found in Technical Topics by G3VA in Radio
>Communication of:
>
>August 1997 p. 77
>
>October 1996 p. 77
>
>73, Dick, PA0SE
>
>
>
>