Message-ID: <002001bedcc7$179cb0a0$fc96b38f@w8k3f0>
From: "Dick Rollema" <d.w.rollema@gironet.nl>
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: Class E RF amplifiers
Date: Mon, 2 Aug 1999 11:11:18 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

>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