Return-Path: Received: from rly-mg06.mx.aol.com (rly-mg06.mail.aol.com [172.20.83.112]) by air-mg08.mail.aol.com (v121.5) with ESMTP id MAILINMG083-a1e4884609e327; Mon, 21 Jul 2008 06:11:05 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mg06.mx.aol.com (v121.5) with ESMTP id MAILRELAYINMG068-a1e4884609e327; Mon, 21 Jul 2008 06:10:42 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1KKsLO-00049V-Iy for rs_out_1@blacksheep.org; Mon, 21 Jul 2008 11:10:14 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1KKsLL-00049M-U0 for rsgb_lf_group@blacksheep.org; Mon, 21 Jul 2008 11:10:11 +0100 Received: from smtp-out-1.talktalk.net ([62.24.128.231] helo=smtp.talktalk.net) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1KKsLI-0001CO-2d for rsgb_lf_group@blacksheep.org; Mon, 21 Jul 2008 11:10:11 +0100 X-Path: TTSMTP X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArcFAOH8g0hZ8o7X/2dsb2JhbAATgi0ygWqDbYFbCpoHiQo Received: from unknown (HELO mal769a60aa920) ([89.242.142.215]) by smtp.talktalk.net with SMTP; 21 Jul 2008 11:10:00 +0100 Message-ID: <002201c8eb19$ef21f930$0301a8c0@mal769a60aa920> From: "mal hamilton" To: "rsgb" Date: Mon, 21 Jul 2008 11:09:59 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: 500 khz TX Content-Type: multipart/alternative; boundary="----=_NextPart_000_001F_01C8EB22.50A38BD0" 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_40_50,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: listenair ; SPF_helo : n X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : n ------=_NextPart_000_001F_01C8EB22.50A38BD0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable My 500 khz TX is made out of recycled components from the junk box. 1940 xtal in osc IC osc chip/IC divider chip/IC driver chip/FET PA class E, then on the drain= side 1940's ceramic inductor (tinned copper wire) out of a TU5B tuning unit, 1950= 's tube TV line output core, rewound for impedence matching FET/50 ohms. LPF using unmarked cores similar to FT200 type. FET out of an old marine tx 1960's vintage.=20 CCT board for chips reworked from an old pre used board. Ferrite chokes in V + line from old smpu, decoupling capacitors and misc it= ems, small heatsink and fan from junk box. Psu for chips 12 regulated, ex surplus Psu for FET rebuilt using ex surplus high capacity capacitors, not regulated The finished package looks neat and tidy and is totally reliable, and no SMO= KE The secret to avoid smoke in class E is to get the FET drain matching netwo= rk spot on to avoid voltage/current spikes during switching. If designed pro= perly you will be in the ball park and just need minor adjustments ie adjust= ing coil tappings while making observations on a 'scope. =20 I used components that I had lying around in junk boxes and the cost was NIL= . This is the TX that I used on 500 khz to work VE1ZZ and RW3ADB on normal CW. 73 De Mal/G3KEV =20 ------=_NextPart_000_001F_01C8EB22.50A38BD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

My 500 khz TX is made out of recycled compo= nents=20 from the junk box.

1940 xtal in osc

IC osc chip/IC divider chip/IC driver chip/= FET PA=20 class E, then on the drain side

1940's ceramic inductor (tinned copper=20 wire) out of a TU5B tuning unit, 1950's tube TV line output c= ore,=20 rewound for impedence matching FET/50 ohms.

LPF using unmarked cores similar to=20 FT200 type.

FET out of an old marine tx 1960's vintage.= =20

CCT board for chips reworked from an old pr= e used=20 board.

Ferrite chokes in V + line from=20= old=20 smpu, decoupling capacitors and misc items, small heatsink and fan from junk= =20 box.

Psu for chips 12 regulated, ex surplus

Psu for FET rebuilt using ex surplus high c= apacity=20 capacitors, not regulated

The finished package looks neat and tidy an= d is=20 totally reliable, and no SMOKE

The secret to avoid smoke in class=20 E is to get the FET drain matching network spot on to avoid=20 voltage/current spikes during switching. If designed properly you will=20= be=20 in the ball park and just need minor adjustments ie adjusting coil=20 tappings while making observations on a 'scope.

I used components that I had lying around i= n junk=20 boxes and the cost was NIL.

This is the TX that I used on 500 khz to wo= rk VE1ZZ=20 and RW3ADB on normal CW.

73 De Mal/G3KEV

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