Return-Path: Received: from rly-db02.mx.aol.com (rly-db02.mail.aol.com [172.19.130.77]) by air-db09.mail.aol.com (v125.7) with ESMTP id MAILINDB091-ab04ab156e0222; Wed, 16 Sep 2009 17:21:56 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-db02.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDB026-ab04ab156e0222; Wed, 16 Sep 2009 17:21:39 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Mo1vy-00067s-U7 for rs_out_1@blacksheep.org; Wed, 16 Sep 2009 22:21:02 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Mo1vy-00067j-II for rsgb_lf_group@blacksheep.org; Wed, 16 Sep 2009 22:21:02 +0100 Received: from sighthound.demon.co.uk ([80.177.174.126]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Mo1vo-0003AP-T5 for rsgb_lf_group@blacksheep.org; Wed, 16 Sep 2009 22:20:55 +0100 Received: from [10.218.2.14] (gammybird.twatt.home [10.218.2.14]) by deerhound.twatt.home (Postfix) with ESMTP id 41FFB3B42D for ; Wed, 16 Sep 2009 21:20:52 +0000 (UTC) Message-ID: <4AB156AF.10900@sighthound.demon.co.uk> Date: Wed, 16 Sep 2009 21:20:47 +0000 From: John P-G User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <9afca2640909161002g67ff5386s580f457dd306ddad@mail.gmail.com> <00a901ca370a$417ecc70$0217aac0@jimdesk> <261B000671B34914A1173F8F77A6D3CF@JimPC> In-Reply-To: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: G7NKS multiple spots 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) Graham wrote: > JIm, > > I think you find that is caused by 50 hz mains hum .... may be a hum > loop in the audio system / pc-tx earthling , not likely to be psu > problem as frequency is 50 (fund) and 150 ( 3 rd harm) > > I had a similar problem with my valve HF set , that was a slight > ripple on the PA HT line caused by the 100% duty cycle of wspr, not > part of the design criteria for ssb/cw , caused spots to appear +/- > 100 Hz due to the full wave rectification in the psu > Oddly though Jame's twin spots of Jim are 100Hz apart: M0BMU 0.503944 M0BMU 0.503844 John -- IP90gg Clousta, Shetland http://gm4slv.blogspot.com