Return-Path: Received: (qmail 76580 invoked from network); 7 Mar 2005 22:32:22 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore03.plus.net with SMTP; 7 Mar 2005 22:32:22 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1D8QoP-00021x-Gi for dave@picks.force9.co.uk; Mon, 07 Mar 2005 22:34:56 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1D8QoO-00021q-Uw for dave@picks.force9.co.uk; Mon, 07 Mar 2005 22:34:53 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim) id 1D8QoL-0004kM-4r for dave@picks.force9.co.uk; Mon, 07 Mar 2005 22:34:49 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1D8QlR-0001MK-61 for rs_out_1@blacksheep.org; Mon, 07 Mar 2005 22:31:49 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1D8QlQ-0001MB-Ln for rsgb_lf_group@blacksheep.org; Mon, 07 Mar 2005 22:31:48 +0000 Received: from imo-m18.mx.aol.com ([64.12.138.208]) by relay.thorcom.net with esmtp (Exim 4.43) id 1D8QlP-0001xZ-5J for rsgb_lf_group@blacksheep.org; Mon, 07 Mar 2005 22:31:48 +0000 Received: from MarkusVester@aol.com by imo-m18.mx.aol.com (mail_out_v37_r3.8.) id l.11.409f71cc (1320) for ; Mon, 7 Mar 2005 17:31:37 -0500 (EST) From: MarkusVester@aol.com Message-ID: <11.409f71cc.2f5e3048@aol.com> Date: Mon, 7 Mar 2005 17:31:36 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 8.0 for Windows sub 6104 X-SPF-Result: relay.thorcom.net: domain of aol.com designates 64.12.138.208 as permitted sender X-Spam-Score: 0.5 (/) X-Spam-Report: autolearn=no,HTML_10_20=0.295,HTML_MESSAGE=0.001,NO_REAL_NAME=0.178 Subject: Re: LF: new on 137kc Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_MESSAGE, HTML_TAG_BALANCE_HTML,NO_REAL_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit Hello Michael,

the coordinates of the Sylt Loran station are 54° 48' 29.975" N, 8° 17' 36.856" E. This is on the southern part of the island, and ranges to Romoe vary from 32 to 46 km. The nominal peak power of the pulses is 250 kW on 100 kHz, so you will have to expect a fieldstrength of 150...100 mV/m. This can produce several volts on a typical amateur-sized Marconi. The problem is mostly that the Loran emissions contain significant spectral energy outside their designated passband (90 - 110 kHz).

- You can try to reduce the interference using a loop receive antenna. The disadvantage is of course that you won't be able to hear any signals from the null directions. You will also have to detune  your transmit antenna during receive to avoid degrading of the loop pattern by mutual coupling.

- To prevent the Loran signal from overloading your receiver frontend, a bandpass filter will probably be mandatory.

- As the pulses are short (< 200 µs), a noise blanker in the receiver can be quite effective. It can however remodulate the Loran repetition rates onto other signals (eg. DCF 39) and create weak spurs which could be confusing in extremely narrowband observations.

I wish you a nice holiday, and success for your first steps on this fascinating band.

73 de Markus, DF6NM


In einer eMail vom 07.03.2005 22:23:42 Westeuropäische Normalzeit schreibt m.peters@peters-placke.de:

yesterday say an other om there is a loran-tx on the island of sylt...
is it correct? is it possible to recieve sigs so nearly? distance from
my holiday qth to sylt is only a few kilometers...