Return-Path: Received: from rly-mf10.mx.aol.com (rly-mf10.mail.aol.com [172.20.29.180]) by air-mf04.mail.aol.com (v125.8) with ESMTP id MAILINMF043-9874b0d19923a0; Wed, 25 Nov 2009 06:48:47 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mf10.mx.aol.com (v125.7) with ESMTP id MAILRELAYINMF105-9874b0d19923a0; Wed, 25 Nov 2009 06:48:36 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NDGLA-0002YI-3L for rs_out_1@blacksheep.org; Wed, 25 Nov 2009 11:47:20 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NDGL9-0002Y9-K7 for rsgb_lf_group@blacksheep.org; Wed, 25 Nov 2009 11:47:19 +0000 Received: from mail-ew0-f223.google.com ([209.85.219.223]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NDGL8-0000UQ-Sf for rsgb_lf_group@blacksheep.org; Wed, 25 Nov 2009 11:47:19 +0000 Received: by ewy23 with SMTP id 23so1803381ewy.4 for ; Wed, 25 Nov 2009 03:47:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=YmaznSePsZdE2yQx/ryDYSrpuHvodVyPhNIcxFOip8M=; b=wUKR7cNzNb/WAi5Rf59v2oYIcaPavchUiLD56LgfbkvX17A+Uw8VuDkAPfHMlc6qWJ gPARFM8I1yQN/Obeg1Dqv5ou6FiJNji2veQQYlb3S8tD5fyANjx9wL5YZGwsi4U/O4Jq cZJxwo+l9qkaFGHYLiYg98bbHIE59lKvqO0dE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Xy30TarB7tsvNiyG0sfaeGiVwgfzPQUHNgjcW+EyBGA6/GRpUMoS8kLWI1CDpByopT 1GHJ13OTKdEU7s9hI4P4k+ulDByAlbgWEDMGPavhAu4jFkDC8tz2NkACzh7lALTMy2Bq G9LkY06kQkNq2Zup4gba+2Zy8LIJnCaAHZ3RU= MIME-Version: 1.0 Received: by 10.213.0.196 with SMTP id 4mr4056175ebc.41.1259149632755; Wed, 25 Nov 2009 03:47:12 -0800 (PST) In-Reply-To: <000c01ca6db1$04873810$0301a8c0@your91hoehfy9g> References: <000c01ca6db1$04873810$0301a8c0@your91hoehfy9g> Date: Wed, 25 Nov 2009 12:47:12 +0100 Message-ID: From: =?ISO-8859-1?Q?Anton_B=E4rtschi?= To: rsgb_lf_group@blacksheep.org X-Karma: unknown: DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: Class E pa Content-Type: multipart/alternative; boundary=000e0ce045049459360479309eda X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-AOL-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d282.2 ; domain : gmail.com DKIM : pass X-Mailer: Unknown (No Version) --000e0ce045049459360479309eda Content-Type: text/plain; charset=ISO-8859-1 Hi Mal I'm still using a Derivative of the Design from G3YXM's class E 1KW TX on LF. Recently I've built a TX for 500 kHz using the same principle. It works great and delivers up to 500W. Unfortunately only into a dummy load, because 500 kHz is still not allowed here in Switzerland. But at least - I will be ready ;-) 73 de Toni, HB9ASB 2009/11/25 mal hamilton > Ref recent discussion on the subject. > > I use a class E pa on 500 kcs and never get any trouble. > As a general guide use high voltage fets and the fet V should be rated at > about 5 times the supply V and current about 3 times. > You arrive at class E by careful design not by accident. > Having designed and built the PA for the required power and load R usually > 50 ohms adjust into a DL for correct waveform as displayed on a 'scope, this > is important otherwise V spikes and instability will kill the fet. > Install a suitable antenna and match it with a suitable atu to 50 ohms so > when you connect the TX/PA to the antenna they both match. > Check the wave form again and any slight mismatch should be adjusted by the > antenna atu and NOT the pa. > The load does not have to be 50 ohms but this is convenient when testing > with available test gear. > High V fets give more realistic C and Inductor and R values. A good range > for fets is a psu giving 40 - 100 volts ie fets 500volts and a suitable > current rating depending on your power. requirements ie if you need to draw > 5 amps the fet should be rated 15 amps. > These are the general guidelines and work well for me. > Most amateurs seem to use class D amps whereas class E are rare. > > de Mal/G3KEV > > --000e0ce045049459360479309eda Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Mal
I'm still using a Derivative of the Design from G3YXM's= class E 1KW TX on LF. Recently I've built a TX for 500 kHz using the= same principle. It works great and delivers up to 500W. Unfortunately onl= y into a dummy load, because 500 kHz is still not allowed here in Switzerl= and. But at least - I will be ready ;-)
73 de Toni, HB9ASB

2009/11/25 mal hamilt= on <g3kevmal= @talktalk.net>
Ref recent discussion on the subject.=
=A0
I use a class E pa on 500 kcs and nev= er get any=20 trouble.
As a general guide use high voltage= fets and the=20 fet V should be rated at =A0about 5 times the supply V and current about= 3=20 times.
You arrive at class E by careful desi= gn not by=20 accident.
Having designed and built the PA for= the required=20 power=A0and=A0load R usually 50 ohms adjust into a DL for correct waveform= =20 as displayed on a 'scope, this is important otherwise V spikes and ins= tability=20 will kill the fet.
Install a suitable antenna and match= it with a=20 suitable atu to 50 ohms so when you connect the TX/PA to the antenna they= both=20 match.
Check the wave form again and any sli= ght mismatch=20 should be adjusted by the antenna atu and NOT the pa.
The load does not=20 have to be 50 ohms but this is convenient when testing with available test= =20 gear.
High V fets give more realistic C and= Inductor and=20 R values. A good range for fets is a psu giving 40 - 100 volts ie fets 500= volts=20 and a suitable current rating depending on your power. requirements ie if= you=20 need to draw 5 amps the fet should be rated 15 amps.
These are the general guidelines and= work well for=20 me.
Most amateurs seem to use class D amp= s whereas=20 class E are rare.
=A0
de Mal/G3KEV
=A0

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