Return-Path: Received: (qmail 32497 invoked from network); 12 Jul 2004 21:51:26 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore01.plus.net with SMTP; 12 Jul 2004 21:51:26 -0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1Bk8ik-000GBq-0H for dave@picks.force9.co.uk; Mon, 12 Jul 2004 22:52:22 +0100 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim 4.30; FreeBSD) id 1Bk8hn-000PUk-Tf for dave@picks.force9.co.uk; Mon, 12 Jul 2004 21:51:23 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Bk8hc-0003BA-Rc for rs_out_1@blacksheep.org; Mon, 12 Jul 2004 22:51:12 +0100 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Bk8hc-0003B1-Fa for rsgb_lf_group@blacksheep.org; Mon, 12 Jul 2004 22:51:12 +0100 Received: from smtp803.mail.ukl.yahoo.com ([217.12.12.140]) by relay.thorcom.net with smtp (Exim 4.34) id 1Bk8hY-0006N3-UK for rsgb_lf_group@blacksheep.org; Mon, 12 Jul 2004 22:51:12 +0100 Received: from unknown (HELO rogersservices) (james.moritz@81.135.122.241 with login) by smtp803.mail.ukl.yahoo.com with SMTP; 12 Jul 2004 21:51:03 -0000 Message-ID: <001901c46859$949cd260$f17a8751@rogersservices> From: "James Moritz" To: rsgb_lf_group@blacksheep.org References: <40F2CF45.30049.6CA6CC@localhost> Date: Mon, 12 Jul 2004 22:45:41 +0100 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: autolearn=no,RCVD_IN_SORBS=0.1 Subject: LF: Re: Receivers 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-Spam-Filtered: by PlusNet SpamCORE (v3.00) Dear Mike, LF group I have an Icom IC718 transceiver - it tunes down to 30kHz, and has the typical 20dB loss of sensitivity at 136kHz compared to HF. I have the optional 250Hz filter, which is very good for LF, if a bit narrow for HF. With the filter, it needs 1uV for 10dB SNR on 136k. This gives adequate RX sensitivity with my TX wire antenna resonated with a suitable coil - for smaller antennas, a preamp is required. The sensitivity deteriorates as the frequency decreases. The noise blanker doesn't seem to do very much at LF; the preamp causes a loss of sensitivity. The AGC has the effect of turning the LF band noise into a uniform mush, which does not help readability much, and you can't switch it off, but backing off the RF gain improves things a lot. I think it is quite usable for LF, allthough obviously not ideal. Cheers, Jim Moritz 73 de M0BMU ----- Original Message ----- From: Mike Dennison To: Sent: Monday, July 12, 2004 5:49 PM Subject: LF: Receivers > I am compiling a list of receivers and transceivers suitable > for 136kHz.