Return-Path: Received: (qmail 6358 invoked from network); 26 Mar 2002 11:37:24 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by exhibition.plus.net with SMTP; 26 Mar 2002 11:37:24 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 21637 invoked from network); 26 Mar 2002 11:37:15 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 26 Mar 2002 11:37:15 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16pqil-0007km-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 26 Mar 2002 13:10:39 +0000 Received: from imo-r08.mx.aol.com ([152.163.225.104]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16pqik-0007kd-00 for rsgb_lf_group@blacksheep.org; Tue, 26 Mar 2002 13:10:38 +0000 Received: from G0MRF@aol.com by imo-r08.mx.aol.com (mail_out_v32.5.) id l.c6.8c828aa (3858) for ; Tue, 26 Mar 2002 06:32:00 -0500 (EST) From: G0MRF@aol.com Message-ID: Date: Tue, 26 Mar 2002 06:32:00 EST Subject: Re: LF: QRSS / UA land To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Mailer: AOL 6.0 for Windows UK sub 10512 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit In a message dated 3/26/02 6:03:13 AM GMT Standard Time, DK8KW@compuserve.com writes:


... you could also look into some other solutions that should work pretty
well. For example, there is a way to use two xtals that are 137.7 kHz
apart. The frequencies of thos x-tals are mixed. If the two xtals have
approximately the same temperature behaviour, the resulting frequency is
very stabile. You find a possible sulution on the homepage of Peter, DF3LP
at
If all else fails I have a stock of  8.000 and 8.274MHz Xtals.
They mix to give 274kHz and then you can divide by two which produces two antiphase signals at 137kHz suitable for a push pull amplifier.

The circuit is shown as part of a 300W transmitter in the RSGB LF source book and at www.g0mrf.freeserve.co.uk

As a word of encouragement to Alex. I worked a station near Odessa crossband to 40m with normal CW  with about 20 Watts ERP on 136kHz  (G3WSC special permit).   QRSS should be fine even another 20dB down.

If you are really stuck I probably have a breadboard version of the VXO around here somewhere.

Good luck


David  G0MRF