Return-Path: Received: (qmail 28172 invoked from network); 16 Feb 2002 09:54:28 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 16 Feb 2002 09:54:28 -0000 Received: (qmail 10945 invoked from network); 16 Feb 2002 09:54:27 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 16 Feb 2002 09:54:27 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16c1Sb-0004kh-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 16 Feb 2002 09:48:49 +0000 Received: from smtp-1.visp.telinco.net ([212.1.130.1]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16c1Sa-0004kc-00 for rsgb_lf_group@blacksheep.org; Sat, 16 Feb 2002 09:48:48 +0000 Received: from [212.1.150.175] (helo=g4jnt) by smtp-1.visp.telinco.net with smtp (Exim 3.32 #1) id 16c1Hz-0004co-00 for rsgb_lf_group@blacksheep.org; Sat, 16 Feb 2002 09:37:52 +0000 Message-ID: <002b01c1b6cf$1b826360$af9601d4@g4jnt> From: "Andrew Talbot" To: rsgb_lf_group@blacksheep.org Subject: LF: Re: G4JNT "PSK CW" transmission Date: Sat, 16 Feb 2002 09:48:33 -0000 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 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

I made three complete transmissions of the sequence "G4JNT PSK CW " and most of a forth one until 2022z This sequence had 124 dot intervals, including end of text spaces, so repeated every 20.67 minutes. Power output was turned down a bit to 450 Watts for this test.

The phase wobble is due to the GPS locked source in use, it was really designed for longer signalling intervals than this. The PLL is not fully optimised and has a bandwidth of a few seconds, so phase jitter measured over this sort of interval will be seen. However, if it were possible to integrate over the 10 second dot period then make a descision at the end, the jitter would have an almost insignificant effect even at this signalling rate.

Andy G4JNT

phase meter shows a slant over an 800 second obvervation period, but with a bit of imagination the text can be decoded.
See attached screenshot.
The transmission started at 1900 utc in the diagram at 't=0', on the left side.
A certain amount of "phase jitter" is visible but I'm not sure if it was the quite weak signal affected by noise or Andy's GPS-locked generator. Another screenshot with "L.O."-frequency increased by 2 milliHertz is also available on request.

Regards,
Wolf DL4YHF.