Return-Path: Received: from rly-db04.mx.aol.com (rly-db04.mail.aol.com [172.19.130.79]) by air-db08.mail.aol.com (v125.7) with ESMTP id MAILINDB082-ac24b04820b320; Wed, 18 Nov 2009 18:24:04 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-db04.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDB048-ac24b04820b320; Wed, 18 Nov 2009 18:23:57 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NAtrU-0005YL-H5 for rs_out_1@blacksheep.org; Wed, 18 Nov 2009 23:22:56 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NAtrU-0005YC-3i for rsgb_lf_group@blacksheep.org; Wed, 18 Nov 2009 23:22:56 +0000 Received: from sighthound.demon.co.uk ([80.177.174.126]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NAtrS-0005xL-Gn for rsgb_lf_group@blacksheep.org; Wed, 18 Nov 2009 23:22:56 +0000 Received: from [192.168.1.4] (rx1.twatt.home [192.168.1.4]) by deerhound.twatt.home (Postfix) with ESMTP id CA6683B49B for ; Wed, 18 Nov 2009 23:22:51 +0000 (UTC) Message-ID: <4B0481CB.3090308@sighthound.demon.co.uk> Date: Wed, 18 Nov 2009 23:22:51 +0000 From: John P-G User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <572081.7375.qm@web28101.mail.ukl.yahoo.com> In-Reply-To: <572081.7375.qm@web28101.mail.ukl.yahoo.com> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: G7NKS sidebands Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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-IP: 193.82.116.20 X-Mailer: Unknown (No Version) M0FMT wrote: > Hi LF > > I think the issue is intermodulation products caused by over driving > the the linear RF stages of the TX into distortion because when Jim > reduces drive the sidebands petty well disappear at this range. Hello All, This doesn't explain why Jim also RECEIVES multiple spots from strong stations with similar amplitudes and 50/100Hz spacings. Applying Occam's Razor - look initially for one cause - rather than "on transmit there's a TX IMD or PSU hum problem and on RX there's another separate 50Hz problem" There's a 50Hz modulation problem somewhere, but it's most likely a common RX/TX part of the system. Speclab and a known, clean RX system are your friends.... Simplify.... Simplify.... John GM4LSV