Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HTML_MESSAGE,RCVD_IN_DNSWL_MED,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: dmv.com: mailn 1095; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v4BDi5nZ009362 for ; Thu, 11 May 2017 15:44:06 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1d8oKi-0002mB-Dy for rs_out_1@blacksheep.org; Thu, 11 May 2017 14:40:44 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1d8oKh-0002m2-Vd for rsgb_lf_group@blacksheep.org; Thu, 11 May 2017 14:40:43 +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 4.89) (envelope-from ) id 1d8oKe-0005qX-SB for rsgb_lf_group@blacksheep.org; Thu, 11 May 2017 14:40:42 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 565C620E3E for ; Thu, 11 May 2017 15:40:40 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3wNvPd0r11z109y for ; Thu, 11 May 2017 15:40:37 +0200 (CEST) Message-ID: <591469D4.1020401@posteo.de> Date: Thu, 11 May 2017 15:40:36 +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: <579355A36AEE9D4FA555C45D556003AB8FDD90BF@servigilant.vigilant.local> In-Reply-To: <579355A36AEE9D4FA555C45D556003AB8FDD90BF@servigilant.vigilant.local> X-Scan-Signature: 60b21f5b7eb190e65b65540006a87038 Subject: Re: LF: Some improvements in VLF Rx Content-Type: multipart/alternative; boundary="------------010504000001060800020506" 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: RO X-Status: X-Keywords: X-UID: 11669 This is a multi-part message in MIME format. --------------010504000001060800020506 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit PS: There are a number of settings you could improve in this wideband spectrogram. If you send me your usr file i would send you one back with some changes, if you like. Also it may be worth to start a second spectrogram now, centered on 8270 Hz. It could run in 424 uHz which is to 'fast' to display amateur signals (at least the ones which are available these days) but it will give a first impression about the noise background difference between day and night. 73, Stefan Am 08.05.2017 10:57, schrieb VIGILANT Luis Fernández: > Hi VLF > This weekend could fix the QRM problem with the VLF E-probe. There was > a ground loop at the 1pps from GPS > The ground of the GPS (and PC via USB) was routed to the audio > transformer at the VLF signal side, not soundard side > So, the noise was going up by the VLF cable to the probe and caused a > 20dB noise rise in MF/LF in the nearby MiniWhip > The VLF espectrogram has got clearer, but still contaminated. > Specially at night, probably due to street led lights in the area > https://ea5dom.ure.es/grabber/index.html > I'm using a separate first Fet at the probe, connected by aprox 15m TV > coax. Would it be better to use twisted pair or > keep all the preamp up, close to the probe ? > 73 de Luis > EA5DOM > --------------010504000001060800020506 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit PS: There are a number of settings you could improve in this wideband spectrogram. If you send me your usr file i would send you one back with some changes, if you like.

Also it may be worth to start a second spectrogram now, centered on 8270 Hz. It could run in 424 uHz which is to 'fast' to display amateur signals (at least the ones which are available these days) but it will give a first impression about the noise background difference between day and night.

73, Stefan

Am 08.05.2017 10:57, schrieb VIGILANT Luis Fernández:
Hi VLF
 
This weekend could fix the QRM problem with the VLF E-probe. There was a ground loop at the 1pps from GPS
The ground of the GPS (and PC via USB) was routed to the audio transformer at the VLF signal side, not soundard side
 
So, the noise was going up by the VLF cable to the probe and caused a 20dB noise rise in MF/LF in the nearby MiniWhip
The VLF espectrogram has got clearer, but still contaminated. Specially at night, probably due to street led lights in the area
 
I'm using a separate first Fet at the probe, connected by aprox 15m TV coax. Would it be better to use twisted pair or
keep all the preamp up, close to the probe ?
 
73 de Luis
EA5DOM

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