Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.6 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,URIBL_SBL,URIBL_SBL_A autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mailn.lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id uBEEvQCG022402 for ; Wed, 14 Dec 2016 15:57:27 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cHAwi-0002dO-DI for rs_out_1@blacksheep.org; Wed, 14 Dec 2016 14:54:16 +0000 Received: from [195.171.43.34] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cHAwh-0002dF-Sf for rsgb_lf_group@blacksheep.org; Wed, 14 Dec 2016 14:54:15 +0000 Received: from smarthost03c.mail.zen.net.uk ([212.23.1.22]) by relay2.thorcom.net with esmtp (Exim 4.87) (envelope-from ) id 1cHAwc-0002aL-7r for rsgb_lf_group@blacksheep.org; Wed, 14 Dec 2016 14:54:14 +0000 Received: from [82.70.254.222] (helo=OfficeWin7.lan) by smarthost03c.mail.zen.net.uk with esmtp (Exim 4.80) (envelope-from ) id 1cHAwb-0007wW-Do for rsgb_lf_group@blacksheep.org; Wed, 14 Dec 2016 14:54:09 +0000 Date: Wed, 14 Dec 2016 14:54:09 +0000 From: Chris Wilson Organization: Gatesgarth Developments X-Priority: 3 (Normal) Message-ID: <342644544.20161214145409@chriswilson.tv> To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Originating-smarthost03c-IP: [82.70.254.222] Feedback-ID: 82.70.254.222 X-Scan-Signature: 739d4fb39bd02fc5a2de5437a39bb056 Subject: LF: Circa 144kHz noise hump Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.75 Status: O X-Status: X-Keywords: X-UID: 9796 14 December 2016 Thanks to all who have helped both here and by e-mail. Turning off the mains into the house and workshop and running my laptop on internal battery and the IDC receiver on a 12V accumulator saw a very slight degradation in the noise, but nothing of significance. It has been mentioned this noise hump may be caused by a mixing of high level signals and the way the front end of the IDC receiver is constructed. i have had the idea of using HDSDR to record this noise in RF and AF format. If someone using HDSDR has the time and inclination to download the .wav file and play it on their PC maybe their experience could suggest what it may be? HDSDR allows one to look at it in SSB or AF or even FM modes. I recorded about a minute of it. the pulsing noise at about 1.5 second or so intervals is the electric cattle fence, and yes, I turned that off as a fisrt step in ID'ing it, plus it goes off if the mains to the house is turned off. It made no difference to the noise hump :( The file is at: http://www.first.tv/HDSDR.zip it's fairly big. Thanks for reading! -- Best regards, Chris 2E0ILY mailto:chris@chriswilson.tv My part time LF grabber is at http://www.chriswilson.tv/grabber.html