Return-Path: Received: from rly-de02.mx.aol.com (rly-de02.mail.aol.com [172.19.170.138]) by air-de01.mail.aol.com (v125.7) with ESMTP id MAILINDE014-4b94afbd9ec378; Thu, 12 Nov 2009 04:48:34 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-de02.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDE024-4b94afbd9ec378; Thu, 12 Nov 2009 04:48:30 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1N8WH8-0006DY-Ko for rs_out_1@blacksheep.org; Thu, 12 Nov 2009 09:47:34 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1N8WH8-0006DP-1D for rsgb_lf_group@blacksheep.org; Thu, 12 Nov 2009 09:47:34 +0000 Received: from mtaout03-winn.ispmail.ntl.com ([81.103.221.49]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1N8WH6-0002vO-E2 for rsgb_lf_group@blacksheep.org; Thu, 12 Nov 2009 09:47:33 +0000 Received: from know-smtpout-1.server.virginmedia.net ([62.254.123.1]) by mtaout03-winn.ispmail.ntl.com (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20091112094722.BPZK17277.mtaout03-winn.ispmail.ntl.com@know-smtpout-1.server.virginmedia.net> for ; Thu, 12 Nov 2009 09:47:22 +0000 Received: from [86.27.93.99] (helo=jimdesk) by know-smtpout-1.server.virginmedia.net with esmtp (Exim 4.63) (envelope-from ) id 1N8WGv-0006r8-So for rsgb_lf_group@blacksheep.org; Thu, 12 Nov 2009 09:47:22 +0000 From: "James Cowburn" To: References: <4AFB477C.5090604@sighthound.demon.co.uk> <001501ca6326$ff28c710$0617aac0@jimdesk> <00f301ca6329$8ba907c0$0900a8c0@lark> <001901ca632a$d3356ab0$0617aac0@jimdesk> <011201ca6332$23e930c0$0900a8c0@lark> Date: Thu, 12 Nov 2009 09:47:20 -0000 Message-ID: <000301ca637d$20bd9e40$0617aac0@jimdesk> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 Thread-Index: AcpjMlBJFXeN4Z2BTFaI0bB3F1Ju2gASmEMg In-Reply-To: <011201ca6332$23e930c0$0900a8c0@lark> X-Cloudmark-Analysis: v=1.0 c=1 a=sKl0yPpJp1MA:10 a=F3M5lZpKAAAA:8 a=8RloEfZUAAAA:8 a=ucZTuQLQxCvYkBNsjUkA:9 a=iS_JaMjvURPXLmeMT3wA:7 a=mO9LmdeeNFAFhky74vPi75PM7IgA:4 a=wk6s2zzMB60A:10 a=O58u2wXj750A:10 a=SOC50V_PD97yeAWx:21 a=jCWr6k8wQ4GK5RpH:21 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: RE: Re: RE: Re: RE: G7NKS multiple WSPR decodes! Content-Type: text/plain; charset="us-ascii" 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 Hi Alan Thanks for the pointers here. Very useful. As it transpires, the laptop psu is now interfering on Rx so a loop has opened up somewhere. I'm going to dismantle the whole set up and re-wire/reroute from scratch....god help me!! I should have taken up stamp collecting as a hobby! With best regards Jim Dr. James Cowburn -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Alan Melia Sent: 12 November 2009 00:25 To: rsgb_lf_group@blacksheep.org Subject: LF: Re: RE: Re: RE: G7NKS multiple WSPR decodes! Ah the dreaded laptop. Ok the isolation that is agood idea in that case you must make sure you have some Rf grounds somewhere. Laptops seem to float there is not reason (for the digital engineers who designed them anyway) to put an earth on the metalwork. The RF circuitating in those leads might be inducing hum. It might be worth trying an earth on any suitable but of the laptop metalwork....socket pillars ?? It definitely sounds as though it is hum getting into the PC sound system. Good Luck with it. Alan G3NYK ----- Original Message ----- From: "James Cowburn" To: Sent: Wednesday, November 11, 2009 11:58 PM Subject: LF: RE: Re: RE: G7NKS multiple WSPR decodes! > The soundcard leads are via an opto-isolator interface and the leads from > the interface to laptop are wound on ferrite cores, approx 8 turns each for > tx and rx. > > I will check the mains psu for the dell d610 laptop as that could be > introducing hum or picking up rf from the tx (IC-735). It might need > ferrites on the leads to and from the SMPSU > > I've just turned "the wick" down on the tx/rx inputs and also the rf gain on > ic 735 till the needle just shifted in case it was being over-driven so I'll > see how that works. > > Not a prob when I was QRPpp but as sigs improve with dark nights I'd noticed > it too > > Thanks to John and others for heads up and suggestions > > With best regards > > > Jim > > > Dr. James Cowburn G7NKS > -----Original Message----- > From: owner-rsgb_lf_group@blacksheep.org > [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Alan Melia > Sent: 11 November 2009 23:49 > To: rsgb_lf_group@blacksheep.org > Subject: LF: Re: RE: G7NKS multiple WSPR decodes! > > Hi Jim what kind of PC are you using. If a desktop are to sure it has the > mains safety earth connected.....I have come across this problem before some > 3 connecter IEC moulded leads with only two wires in them!! If a laptop then > unless you use a radio earth that may all be floating. Sometimes it is > necessary to use an tranformer on the audio leads to and from the PC to gain > isolation from the hum and noise. I use old telephone hybrid transformers > 600ohm to 600 ohm ferrite cored. > > Best Wishes > Alan G3NYK > > ----- Original Message ----- > From: "James Cowburn" > To: > Sent: Wednesday, November 11, 2009 11:30 PM > Subject: LF: RE: G7NKS multiple WSPR decodes! > > > > Hi John > > > > I'll have a look see. I've noticed on strong sigs from me (few and far > > between!) I get multiple decodes +50 and -50. I'm not aware of any > obvious > > mains hum if I monitor my outgoing sigs and all leads are wound on ferrite > > cores, but clearly something is amiss. > > > > I shall look into it and see what I can find > > > > Cheers for the heads up > > > > With best regards > > > > > > Jim > > > > > > Dr. James Cowburn > > -----Original Message----- > > From: owner-rsgb_lf_group@blacksheep.org > > [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of John P-G > > Sent: 11 November 2009 23:24 > > To: rsgb_lf_group@blacksheep.org > > Subject: LF: G7NKS multiple WSPR decodes! > > > > Jim. LF > > > > It looks like G7NKS has a 50/100Hz problem on the audio - both in TX and > > RX directions - there are up to 3 decodes by Jim of a single station (eg > > G3YXM), spaced by 50 & 100Hz and I see also that M0BMU is also reporting > > multiple decodes of G7NKS with the same 50/100Hz spacing. > > > > Jim, have you some mains hum affecting the audio in/out of the PC? > > > > Cheers, > > > > John > > GM4SLV > > > > > > > > >