Return-Path: Received: (qmail 27604 invoked from network); 22 Feb 2003 21:45:36 -0000 Received: from netmail01.services.quay.plus.net (212.159.14.219) by mailstore with SMTP; 22 Feb 2003 21:45:36 -0000 Received: (qmail 24800 invoked by uid 10001); 22 Feb 2003 21:45:35 -0000 Received: from post.thorcom.com (193.82.116.70) by netmail01.services.quay.plus.net with SMTP; 22 Feb 2003 21:45:35 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18mhOe-0007zY-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 22 Feb 2003 21:41:24 +0000 Received: from [212.135.6.14] (helo=smarthost4.mail.uk.easynet.net) by post.thorcom.com with esmtp (Exim 4.12) id 18mhOe-0007zP-00 for rsgb_lf_group@blacksheep.org; Sat, 22 Feb 2003 21:41:24 +0000 Received: from tnt-2-202.easynet.co.uk ([195.40.196.202] helo=erica) by smarthost4.mail.uk.easynet.net with smtp (Exim 4.10) id 18mhOR-000OWR-00 for rsgb_lf_group@blacksheep.org; Sat, 22 Feb 2003 21:41:22 +0000 Message-ID: <001001c2dabb$aa2842e0$cac428c3@erica> From: "g3ldo" To: rsgb_lf_group@blacksheep.org References: <002c01c2d9a8$142cab00$0500a8c0@charter.net> Date: Sat, 22 Feb 2003 21:44:13 -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: Drooping signal Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.5 required=6.0tests=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 Hi John > Here's the visual evidence. John Andrews sent (direct) a capture of my signal on the morning of the 22nd when a fragment was received by KL1X. I feel this droopy signal needs general explanation so I have replied via the reflector. John Thanks very much for the Jpeg. It turned out to be a much more useful capture than just a record of frequency instability. While I was transmitting I was monitoring my transmission on Argo and noticed the frequency drifting low. I think you know that I have my transmitter in a shed at the bottom of the garden, together with the DDS driver. At this time of the year the temperature can drop to as low a -8C. The DDS frequency is sensitive to temperature but if the shed stays cold it is unaffected by the transmitter being on or my presence. When the temperature in the transmitter shack is around 0C then heat from the transmitter can raise the temperature by about 1 to 2 deg C. The DDS is moved 0.1Hz per change of 1 deg C. When I noticed the frequency downward drift I went down and opened the door of the transmitter shed - hence the reversal of frequency drift. Now while this is hardly good engineering practice the signal characteristic enabled me to compare it with the signal received by KL1X and confirm it was a D he received at the lowest part of the dip of the frequency drift. The plan is to eventually have the DDS unit, plus a divide by 10 circuit and driver, in the house shack by the side of the receiver. This will give me 0.1Hz resolution and more stability - and less 'characteristic'. Regards, Peter, G3LDO e-mail Web