Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 42CD838000088; Wed, 2 May 2012 09:48:38 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SPZt7-00082x-5d for rs_out_1@blacksheep.org; Wed, 02 May 2012 14:46:37 +0100 Received: from [109.69.104.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SPZt6-00082o-HB for rsgb_lf_group@blacksheep.org; Wed, 02 May 2012 14:46:36 +0100 Received: from mailt.toya.net.pl ([217.113.224.9] ident=postfix) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1SPZt5-00023H-7P for rsgb_lf_group@blacksheep.org; Wed, 02 May 2012 14:46:36 +0100 Received: from mail.toya.net.pl (localhost.localdomain [127.0.0.1]) by mail.toya.net.pl (Postfix) with ESMTP id 189EA2000085A for ; Wed, 2 May 2012 15:46:32 +0200 (CEST) Received: by mail.toya.net.pl (Postfix, from userid 5001) id 0DE5D20000761; Wed, 2 May 2012 15:46:32 +0200 (CEST) Received: from [192.168.1.101] (unknown [10.3.157.90]) (Authenticated sender: unimlyn@toya.net.pl) by mail.toya.net.pl (Postfix) with ESMTPSA id 53CD22000085A for ; Wed, 2 May 2012 15:46:23 +0200 (CEST) Message-ID: <4FA13AAF.1070806@toya.net.pl> Date: Wed, 02 May 2012 15:46:23 +0200 From: Piotr Mlynarski User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; pl; rv:1.9.2.28) Gecko/20120306 Thunderbird/3.1.20 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4FA04D47.6070701@iup.uni-heidelberg.de> In-Reply-To: <4FA04D47.6070701@iup.uni-heidelberg.de> X-AV-Checked: ClamAV using ClamSMTP X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: Basic LF understanding Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: quoted-printable X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: 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-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:434376032:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d60cd4fa13b362653 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none W dniu 2012-05-01 22:53, Stefan Sch=E4fer pisze: > LF! > > Has someone a very good link to basic understanding about LF? I mean=20 > the LF amateur radio stuff, all which one has to learn when starting=20 > rx-wise in our hobby! Maybe some ideas and examples, a good=20 > compliation. Not to complex and focusing on 137 kHz amateur radio? > For newcomers in the "LF-transmit-world" i recommend ON7YD's page=20 > http://www.strobbe.org/on7yd/136ant/ > Is there maybe something for receive newcomers? > > A collection of some links may help as well... > > Thanks in advance. > > 73, Stefan/DK7FC > > Hi Stefan, LF In my opinion the basic info for ' LF receive newcomers' should be=20 divided into 3 topics. While the first one shoud provide knowledge about propagation of long=20 waves the second one should provide basic information about modulation techniques used at=20 LF. The third part might cover technical ideas/schematics concerning receiving antennae ( either active=20 or passive), filters, pre/ampifiers impedance matching issues etc... - here you are an expert... :) Concerning the modulation techniques i would still recommend the=20 excellent Rik, ON7YD website but with different page: http://www.qsl.net/on7yd/136narro.htm#QRSS IMO, this is the best starting info i have ever found... According to LF propagation effects - i would definitely ask Alan Melia=20 for the info upon this issue For those who like to do little math ( just for fun or for more serious=20 purposes) i would advice to look at the following paper: http://www.qsl.net/dk2fi/lw/lfprop1.pdf those above are just first thoughts etc.... Yours,=20 Piotr, sq7mpj qth:/Lodz/