Return-Path: Received: (qmail 22961 invoked from network); 26 Nov 2001 18:26:05 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 26 Nov 2001 18:26:05 -0000 Received: (qmail 23856 invoked from network); 26 Nov 2001 18:26:13 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 26 Nov 2001 18:26:13 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 168QMj-0000vN-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 26 Nov 2001 18:20:25 +0000 Received: from mta2-rme.xtra.co.nz ([210.86.15.130]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 168QMi-0000uv-00 for rsgb_lf_group@blacksheep.org; Mon, 26 Nov 2001 18:20:24 +0000 Received: from xtr743187 ([202.27.181.30]) by mta2-rme.xtra.co.nz with SMTP id <20011126181908.XRAB5089.mta2-rme.xtra.co.nz@xtr743187> for ; Tue, 27 Nov 2001 07:19:08 +1300 Message-ID: <00a601c176a7$48b32300$1eb51bca@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <7D653C9C42F5D411A27C00508BF8803D55C64A@PDW-MAIL-R1> Subject: LF: Doppler shift on LF? Date: Tue, 27 Nov 2001 07:20:36 +1300 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 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: Hi all, Andy G4JNT wrote: > Read the article on Dopplergrams by G3PLX in RadCom three or four years ago > ... > There is likely to be several Hz of Doppler shift on that frequency at night > time. > > Guess who forgot that simple fact last night ! >From monitoring of overseas beacons and LF standard frequency and time signals, with significant skywave component in the DX paths (signal strength is much higher at night time), I have not seen evidence of frequency shift from the assumed stable frequency of the transmitter. If there is Doppler shift, it would seem to have limits of no more than 0.1 Hz for carriers around 200 kHz, and is probably proportionally less for lower frequencies. 73, Bob ZL2CA