Return-Path: Received: (qmail 53572 invoked from network); 27 Mar 2004 13:52:37 -0000 Received: from unknown (HELO ptb-mxscan01.plus.net) (212.159.14.235) by ptb-mailstore04.plus.net with SMTP; 27 Mar 2004 13:52:37 -0000 Received: (qmail 54322 invoked from network); 27 Mar 2004 13:52:37 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore01.plus.net (212.159.14.215) by ptb-mxscan01.plus.net with SMTP; 27 Mar 2004 13:52:36 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim 4.30; FreeBSD) id 1B7EEm-000Dpn-Fl for dave@picks.force9.co.uk; Sat, 27 Mar 2004 13:52:36 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1B7EDz-0000fc-7P for rs_out_1@blacksheep.org; Sat, 27 Mar 2004 13:51:47 +0000 Received: from [213.232.95.59] (helo=relay.salmark.net) by post.thorcom.com with esmtp (Exim 4.14) id 1B7EDy-0000fT-P4 for rsgb_lf_group@blacksheep.org; Sat, 27 Mar 2004 13:51:46 +0000 Received: from carbon.btinternet.com ([194.73.73.92]) by relay.salmark.net with esmtp (Exim 4.24) id 1B7EDv-0002hI-PH for rsgb_lf_group@blacksheep.org; Sat, 27 Mar 2004 13:51:43 +0000 Received: from [213.122.203.35] (helo=rogersservices) by carbon.btinternet.com with esmtp (Exim 3.22 #25) id 1B7EDv-0001R9-00 for rsgb_lf_group@blacksheep.org; Sat, 27 Mar 2004 13:51:43 +0000 X-Bad-Message-ID: no DNS (rogersservices) Message-ID: <001801c41402$059111e0$23cb7ad5@rogersservices> From: "James Moritz" To: rsgb_lf_group@blacksheep.org References: <000001c41358$2d534c20$fce8c593@RD40004> <000901c413ed$a230caa0$ee9bfea9@oben> Date: Sat, 27 Mar 2004 13:47:17 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 X-Spam-Score: 0.1 (/) X-Spam-Report: 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [194.73.73.92 listed in dnsbl.sorbs.net] [213.122.203.35 listed in dnsbl.sorbs.net] Subject: LF: Re: Re: Re: Receiving Setup Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-PN-SPAMFiltered: yes X-Spam-Rating: 2 > Hello Jim &LF-group, > is the TX-antenne detuned, while you're receiving on the loop? (so ther is > no nearfield-coupling from the big one to the loop)? > > Regards, Peter, dj9dw Dear Peter, LF Group, Yes - The antenna is matched with a series loading coil, and a seperate matching transformer, connecting to the TX via 50ohm coax. Essentially, the TX/RX relay open circuits the feed to the antenna, leaving the matching transformer secondary inductance in series with the loading coil. This adds several hundred uH to the loading inductance, which seems to be enough to detune the antenna to the point where it has no detectable effect. If the transmit antenna is not detuned, it is possible to hear some increase in 50Hz noise on the loop antenna, but the increase is not very dramatic. Cheers, Jim Moritz 73 de M0BMU