Return-Path: Received: (qmail 25440 invoked from network); 6 Sep 2001 15:44:21 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 6 Sep 2001 15:44:21 -0000 X-Priority: 3 Received: (qmail 23149 invoked from network); 6 Sep 2001 15:42:25 -0000 X-MSMail-Priority: Normal Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 6 Sep 2001 15:42:25 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15f19U-0004QH-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 06 Sep 2001 16:33:12 +0100 Received: from hestia.herts.ac.uk ([147.197.200.9]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15f19T-0004QC-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Sep 2001 16:33:11 +0100 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 15f18q-0003uu-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Sep 2001 16:32:32 +0100 Received: from [147.197.232.252] (helo=mj9ar) by gemini.herts.ac.uk with smtp (Exim 3.22 #2) id 15f18p-0000jP-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Sep 2001 16:32:31 +0100 From: "James Moritz" Organization: University of Hertfordshire To: rsgb_lf_group@blacksheep.org Date: Thu, 6 Sep 2001 16:35:01 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit Subject: LF: Re: QRG of SAQ transmission X-Mailer: Pegasus Mail for Win32 (v3.11) Message-ID: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Dear Alberto, LF Group, I recorded a .wav file of the SAQ broadcast yesterday. I checked the frequency using Spec Lab, and the calibration factors I use for Wolf reception. The frequency wobbles around slightly - it was about 17.220kHz +/-5Hz. A distinctive feature of the SAQ signal is the backwave - with the key up, the TX power is only reduced by about 20dB, not completely eliminated. At my QTH this is audible, and shows up as a rather drifty carrier on the spectrogram. The backwave frequency was about 10-20Hz lower than the main signal. Incidentally, the error on the sampling rate of my soundcard is - 0.56% with 8kHz sample rate, +0.41% at 11k sample rate. So errors of this sort can arise due to the soundcard alone. Cheers, Jim Moritz 73 de M0BMU