Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD,SPF_PASS autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u6BLkOKO027777 for ; Mon, 11 Jul 2016 23:46:24 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bMish-0000Ho-BW for rs_out_1@blacksheep.org; Mon, 11 Jul 2016 22:36:47 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bMisg-0000Hf-Gy for rsgb_lf_group@blacksheep.org; Mon, 11 Jul 2016 22:36:46 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1bMise-0002pi-HI for rsgb_lf_group@blacksheep.org; Mon, 11 Jul 2016 22:36:45 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 24E4A20ABB for ; Mon, 11 Jul 2016 23:36:42 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3rpJMF41z7zyQ2 for ; Mon, 11 Jul 2016 23:36:40 +0200 (CEST) Message-ID: <57841167.7090707@posteo.de> Date: Mon, 11 Jul 2016 23:36:39 +0200 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <5772DAC0.7080001@df3lp.de> <5773CA12.50009@posteo.de> <5773D53A.5070900@abelian.org> <577B9E96.8070807@posteo.de> <577CA9CF.6070303@abelian.org> <577F9982.50909@posteo.de> <578253D5.8000907@posteo.de> <57825889.8000609@posteo.de> In-Reply-To: <57825889.8000609@posteo.de> X-Scan-Signature: c0336009bd9bab526ca27d297ea7579a Subject: ULF: 7.9 km distance on the 101 km band Content-Type: text/plain; charset=UTF-8; format=flowed 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 2.56 on 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 8362 Hi all, Today i woke up early in the morning, 05:00 AM, drunk a coffee and drove on the hill where i intended to receive my own 100 nW ERP ULF signal in a distance of 7.9 km. This is the path and locations: http://no.nonsense.ee/qth/map.html?qth=JN49JL01LT&from=JN49IK00WD The first time i used the portable stereo recorder with PPS+NMEA on the right channel. 130 minutes were recorded. The receive antenna was an active E field antenna, modified for ULF reception. The RX location is a tower on a hill, 570m ASL. The antenna was mounted in about 35m AGL. The tower is quite distant from the city and villages but there is electricity, so the QRM / mains hum was terrible! A first spectrogram shwing the unfiltered signal over the recording time: https://dl.dropboxusercontent.com/u/19882028/ULF/ULF_Teltschikturm_wide_unfiltered.png When applying Paul's hum filter (implemented in SpecLab) it looks MUCH better: https://dl.dropboxusercontent.com/u/19882028/ULF/ULF_Teltschikturm_wide_humfil.png Concentrated arround the interesting range: https://dl.dropboxusercontent.com/u/19882028/ULF/ULF_Teltschikturm_1k-5k_humfil.png Then a band pass filter and NB was applied to generate narrow band spectrograms. Considering the strong mains hum i didn't expect much BUT, i've got a very clear peak in 424 uHz: https://dl.dropboxusercontent.com/u/19882028/ULF/ULF_Teltschikturm_424uHz_NB_humfil.png The average SNR is about 15 dB, the best peak was at 20 dB SNR, much more than i expected. Now, 7.9 km is the best distance so far on the 101 km band. That's 49% of the far field border distance. The nice SNR makes me optimistic to see the signal in the far field. A next step should be a distance of about 17 km. It still looks like i am not band noise limited on the RX side, so maybe there can be an improvement of a few dB. Also i am planning to try a loop in the next test. Preparations will be done in a few minutes :-) The idea is to use a 4 turn 40m circumference (slightly) resonated loop... Certainly it would be better to show a somewhat modulated signal to get a better proof that it's actually my signal, however i am still waiting for a significant peak on Paul's RX site, so i don't want to interrupt the transmission (15 days now). I checked other frequencies like 2971 and 2969 Hz, didn't find a stable signal, so there is no cross-talk from the PPS signal. 73, Stefan