Return-Path: Received: (qmail 4914 invoked from network); 13 Aug 2002 18:54:14 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 13 Aug 2002 18:54:14 -0000 Received: (qmail 1445 invoked from network); 13 Aug 2002 18:54:27 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 13 Aug 2002 18:54:26 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17eiUu-0002Rf-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 13 Aug 2002 21:42:36 +0100 Received: from neptune.imagenisp.com ([204.244.138.19]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17eiUs-0002Ra-00 for rsgb_lf_group@blacksheep.org; Tue, 13 Aug 2002 21:42:35 +0100 Received: from jsm (gi106.imagenisp.com [204.244.17.114]) by neptune.imagenisp.com with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2653.13) id QZ49MC4C; Tue, 13 Aug 2002 11:52:23 -0700 Message-ID: <000a01c242fb$2b68ace0$7211f4cc@jsm> From: "Steve McDonald" To: rsgb_lf_group@blacksheep.org References: <6a.23b88f69.2a798441@aol.com> <00a301c238e9$2266e7e0$389437d2@xtr743187> Subject: LF: Oscillator Stabilty for QRSS? Date: Tue, 13 Aug 2002 11:56:42 -0700 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit

Perhaps someone who has already 'been there' can offer their advice.

I would like to start building the exciter stages for what will be my 136KHz tx (hopefully we will have access to the band within the year!). The DJ1ZB exciter (modified by DF3LP) is the circuit that I am questioning. It mixes two xtal controlled 4MHz oscillators, 136 KHz apart, to extract the 136KHz signal. Can I build two VFO's, somehwere around 1MHz and set them 136KHz apart, that will be stable enough to handle QRSS work? I am worried about drift but also thinking that they may be stable enough if kept in the 1 - 2MHz region. As well, they should (if identical) drift by the same amount and thus be self-correcting? Is this a reasonable avenue to pursue or should I just break down and buy a couple of xtals??

Steve / VE7SL Mayne Island, BC