Return-Path: Received: (qmail 27772 invoked from network); 19 Feb 2003 21:16:40 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 19 Feb 2003 21:16:40 -0000 Received: (qmail 15103 invoked from network); 19 Feb 2003 21:16:39 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 19 Feb 2003 21:16:38 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18lbYB-0007EI-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 19 Feb 2003 21:14:43 +0000 Received: from [212.135.6.14] (helo=smarthost4.mail.uk.easynet.net) by post.thorcom.com with esmtp (Exim 4.12) id 18lbYA-0007E9-00 for rsgb_lf_group@blacksheep.org; Wed, 19 Feb 2003 21:14:42 +0000 Received: from tnt-3-40.easynet.co.uk ([195.40.202.40] helo=erica) by smarthost4.mail.uk.easynet.net with smtp (Exim 4.10) id 18lbY8-000OaR-00 for rsgb_lf_group@blacksheep.org; Wed, 19 Feb 2003 21:14:41 +0000 Message-ID: <005a01c2d85c$6c14f9a0$28ca28c3@erica> From: "g3ldo" To: rsgb_lf_group@blacksheep.org References: <5.2.0.9.2.20030219164801.00b27df0@pop.sapo.pt> <005e01c2d83e$bc24de60$09dc9384@jka> Date: Wed, 19 Feb 2003 21:17:34 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Frequency accuracy Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=-0.3 required=6.0tests=QUOTED_EMAIL_TEXT,REFERENCES,SPAM_PHRASE_00_01, USER_AGENT_OEversion=2.43 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Brian Rogerson said > > Hi Alan, I transmitted for a short period this morning on 137774 or > thereabouts > > using my original DDSVFO if that sheds any light. 73, Brian > John Andrews, W1TAG said. > Never having attempted integral calculus on an 8-bit microcontroller, how > did you train that DDS to perform that feat? Or do you just have a little > warm-up problem? > http://webpages.charter.net/w1tag/files/aqcldo2.jpg I switched my DDS off once at the end of a transmission, then switched it back on again because conditions were better than I thought. It took half an hour for it to settle down, exhibiting just over one Hz drift diring the warm up period. I leave it switched on all the time now. I do get some long term drift because the DDS unit is located in the outside shack and it gets rather cold there - about -1deg C at the moment. I am not sure of my exact frequency. My DDS readout for this T/A and KL stuff is 137,773 and I thought my frequency was actually 137,773.5. I had calibrated Argo on 60kHz with Rugby but the offset does not seem constant when the receiver frequency is changed. >From W3EEE's Argo capture my frequency appears to be 137,772.9, about 1Hz lower than Laurie. I had a slow 0.1Hz drift low due to the shack warming up before the signals disappeared. So, using the W3EEE display as a reference, I will be transmitting on 137.773 from say 0500z tomorrow morning. I will cut down the inter-character gaps and send my complete call. Received a very interesting 3D display of Laurie's and my transmission. This shows Laurie's signal a couple of dB up on mine. Regards, Peter, G3LDO e-mail Web >