Return-Path: Received: from mtain-di04.r1000.mx.aol.com (mtain-di04.r1000.mx.aol.com [172.29.64.8]) by air-me08.mail.aol.com (v129.4) with ESMTP id MAILINME082-8bbd4cd684142bc; Sun, 07 Nov 2010 05:48:53 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-di04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7CEA3380000A5; Sun, 7 Nov 2010 05:48:50 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PF2mL-0003gU-Bs for rs_out_1@blacksheep.org; Sun, 07 Nov 2010 10:47:17 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PF2mL-0003gL-0f for rsgb_lf_group@blacksheep.org; Sun, 07 Nov 2010 10:47:17 +0000 Received: from smtp-vbr5.xs4all.nl ([194.109.24.25]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PF2mI-0003ba-Fl for rsgb_lf_group@blacksheep.org; Sun, 07 Nov 2010 10:47:16 +0000 Received: from pc-roelof (ndb.demon.nl [82.161.81.65]) by smtp-vbr5.xs4all.nl (8.13.8/8.13.8) with ESMTP id oA7Al7rS081859 for ; Sun, 7 Nov 2010 11:47:12 +0100 (CET) (envelope-from roelof@ndb.demon.nl) To: rsgb_lf_group@blacksheep.org References: <20101101233708.02b5f67d@opc1> <007b01cb7a91$ceb8df60$4001a8c0@lark> <187038.8742.qm@web86705.mail.ird.yahoo.com> <20101106233741.0895ce48@opc1> Date: Sun, 07 Nov 2010 11:47:03 +0100 MIME-Version: 1.0 From: "Roelof Bakker" Message-ID: In-Reply-To: <20101106233741.0895ce48@opc1> User-Agent: Opera Mail/10.63 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Subject: Re: LF: WSPR T/A hole discussion Content-Transfer-Encoding: 7bit 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-sid: 3039ac1d40084cd684127169 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) Hello John, What I tried to explain is that all the stages in the receiver needs to be linear with the AGC switched off, including the LF stage to cope with weak and strong signals present in the band path. Very few receivers are capable of this task. However, switching off the AGC and using the rf gain to adjust the overall gain to decrease the sensitivity just enough to hear the band noise with the antenna connected, helps a lot. I will look into the WSPR case and will report back here. This is interesting stuff anyway. 73, Roelof, pa0rdt