Return-Path: Received: from mtain-mi10.r1000.mx.aol.com (mtain-mi10.r1000.mail.aol.com [172.21.131.168]) by air-di07.mail.aol.com (v129.4) with ESMTP id MAILINDI073-ead04cd6abf0237; Sun, 07 Nov 2010 08:38:56 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mi10.r1000.mx.aol.com (Internet Inbound) with ESMTP id 12A5B38000098; Sun, 7 Nov 2010 08:38:51 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PF5R2-00054f-8y for rs_out_1@blacksheep.org; Sun, 07 Nov 2010 13:37:28 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PF5R1-00054W-Ou for rsgb_lf_group@blacksheep.org; Sun, 07 Nov 2010 13:37:27 +0000 Received: from filter02.i-online.fr ([195.200.78.9]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PF5R0-0004jd-4d for rsgb_lf_group@blacksheep.org; Sun, 07 Nov 2010 13:37:27 +0000 Received: from smtp.qtxt.dns-iol.com ([195.200.78.13]) by filter02.i-online.fr (IceWarp 10.0.7 (2010-02-10)) with ESMTP (SSL) id PYS92715 for ; Sun, 07 Nov 2010 14:37:15 +0100 Received: (qmail 7524 invoked by uid 507); 7 Nov 2010 14:37:11 +0100 Received: from unknown (HELO ?192.168.1.101?) (john.rabson@numeo.fr@217.67.155.178) by smtp.qtxt.dns-iol.com with SMTP; 7 Nov 2010 14:37:11 +0100 Mime-Version: 1.0 (Apple Message framework v1081) From: John Rabson X-Priority: 3 In-Reply-To: Date: Sun, 7 Nov 2010 14:37:18 +0100 Message-Id: References: <20101101233708.02b5f67d@opc1> <007b01cb7a91$ceb8df60$4001a8c0@lark> <187038.8742.qm@web86705.mail.ird.yahoo.com> <20101106233741.0895ce48@opc1> To: rsgb_lf_group@blacksheep.org X-Mailer: Apple Mail (2.1081) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: WSPR T/A hole discussion Content-Type: multipart/alternative; boundary=Apple-Mail-98--555289978 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_20_30,HTML_FONTCOLOR_BLUE, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE 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: 3039400cded24cd6abeb6627 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --Apple-Mail-98--555289978 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii On 7 Nov 2010, at 12:41CET, James Moritz wrote: > ... It is assumed that ... the post-filter stages [of a receiver] only= need to be linear enough not to significantly impair the wanted signal,= and there has to be a trade-off with other inherently non-linear function= s too, such as AGC. In one of his articles in the RSGB Bulletin on building your own (valve-ba= sed) SSB gear, the late G2DAF empahsised that for best results the AF stag= es of a receiver must be designed as if they were part of a HiFi system.= =20 73 John F5VLF --Apple-Mail-98--555289978 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii
On 7 Nov 2010, at 12:41CET, James Moritz wrote:

... It is assumed that ... the post-filter stages [of a receiver] only need to be linear enough not to significantly impair the wanted signal, and there has to be a trade-off with other inherently non-linear functions too, such as AGC.

In one of his articles in the RSGB Bulletin on building your own (valve-based) SSB gear, the late G2DAF empahsised that for best results the AF stages of a receiver must be designed as if they were part of a HiFi system. 

73
John F5VLF


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