Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: * X-Spam-Status: No, score=1.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HTML_MESSAGE,RCVD_IN_DNSWL_MED,RCVD_IN_SORBS_WEB,SPF_PASS autolearn=no 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 lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v4892Jx9028783 for ; Mon, 8 May 2017 11:02:20 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1d7eVB-0007vq-RO for rs_out_1@blacksheep.org; Mon, 08 May 2017 09:58:45 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1d7eVB-0007vh-4D for rsgb_lf_group@blacksheep.org; Mon, 08 May 2017 09:58:45 +0100 Received: from gmy2-mh809.smtproutes.com ([94.186.192.138]) by relay1.thorcom.net with esmtp (Exim 4.89) (envelope-from ) id 1d7eV7-0008B2-LF for rsgb_lf_group@blacksheep.org; Mon, 08 May 2017 09:58:43 +0100 X-Katharion-ID: 1494233908.69670.gmy2-mh809 Received: from servigilant.vigilant.es ([85.60.35.36]) by gmy2-mh809.smtproutes.com [(94.186.192.138)] with ESMTP via TCP (TLSv1/TLS_RSA_WITH_AES_256_CBC_SHA); 08 May 2017 08:58:28 +0000 Received: from servigilant.vigilant.local ([fe80::c40d:8140:d722:5448]) by servigilant.vigilant.local ([fe80::c40d:8140:d722:5448%13]) with mapi id 14.03.0123.003; Mon, 8 May 2017 10:57:49 +0200 From: =?iso-8859-1?Q?VIGILANT_Luis_Fern=E1ndez?= To: "rsgb_lf_group@blacksheep.org" Thread-Topic: Some improvements in VLF Rx Thread-Index: AQHSx9kqLov3ejSO8ky0ZlWew2jd+w== Date: Mon, 8 May 2017 08:57:48 +0000 Message-ID: <579355A36AEE9D4FA555C45D556003AB8FDD90BF@servigilant.vigilant.local> In-Reply-To: <5908F9D1.7030403@posteo.de> Accept-Language: es-ES, en-US Content-Language: es-ES X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [192.168.0.2] MIME-Version: 1.0 X-Scan-Signature: 8ac9f0a1bced50a7ada6578ede3fb6ae Subject: LF: Some improvements in VLF Rx Content-Type: multipart/alternative; boundary="_000_579355A36AEE9D4FA555C45D556003AB8FDD90BFservigilantvigi_" 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: 11626 --_000_579355A36AEE9D4FA555C45D556003AB8FDD90BFservigilantvigi_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi VLF This weekend could fix the QRM problem with the VLF E-probe. There was a gr= ound 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 ________________________________ De: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blackshe= ep.org] En nombre de DK7FC Enviado el: martes, 02 de mayo de 2017 23:28 Para: rsgb_lf_group@blacksheep.org Asunto: Re: LF: SL settings for EbNaut FFT recording ? Hi Luis, Am 02.05.2017 22:51, schrieb VIGILANT Luis Fern=E1ndez: The grabber is now showing full spectrum from 0-24KHz https://ea5dom.ure.es/grabber/index.html OK. There is still some room for improvements :-) The Rx is not at Benidorm in the high tower. It is in the roof of a two lev= el house on top of a 5m pole But clear out from high obstacles and trees On top of a 5m pole is very good. But the location or earth is very contami= nated. The pole is a 50cm x 10mm diameter aluminium rod. Will play with the 10MOhm= resistor and first fet stage with filter. I think this is not necessary now. Better to try to find a cleaner ground a= nd/or location, as you say. The noise at MiniWhip rised 20dB, so must get it appart to keep the ear at MF/LF. Yes, LF and MF stays important too! :-) The power supply is a 12V transformer shared with the MiniWhip Maybe this causes a ground loop which picks up the hum. Could explain why L= F/MF became worse as well. Will test another one just for the VLF probe and with better filtering. Or try a battery in a first step and see the difference. A separate small t= ransformer supply is certainly a good decision. The GND of the antenna is separated from mains earth and there is an audio transformer to the PC soundcard FB. BTW. What I'm getting from SL is one FFT file 112Kb size every hour as Mark= us said But how can I merge all the files of a 8h transmission like the one your ar= e running now ? Each file covers 8.9 hours. They are just overlapping so that you can selec= t the closest one (lowest start time offset). I don't know the exact settin= gs though. I would recommend to set the FFT center frequency to 8270.1 Hz. Your signal in your grabber looks stronger than the previous transmissions It is the same antenna current though. 73, Stefan --_000_579355A36AEE9D4FA555C45D556003AB8FDD90BFservigilantvigi_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi VLF
 
This weekend could fix the QRM pr= oblem 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 sound= ard 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 clea= rer, 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 twist= ed pair or
keep all the preamp up, close to = the probe ?
 
73 de = Luis
EA5DOM
De: owner-rsgb_lf_group@blacksheep.= org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: martes, 02 de mayo de 2017 23:28
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: SL settings for EbNaut FFT recording ?

Hi Luis,

Am 02.05.2017 22:51, schrieb VIGILANT Luis Fern=E1ndez:
The grabber is now showing full spectrum from 0-24KHz
OK. There is still some room for improvements :-)

The Rx is not at Benidorm in the high tower. It is in the roof of a tw= o level house on top of a 5m pole
But clear out from high obstacles and trees
On top of a 5m pole is very good. But the location or earth is very contami= nated.
The pole is a 50cm x 10mm diameter aluminium rod. Will play with the 10MOhm= resistor and first fet stage
with filter.
I think this is not necessary now. Better to try to find a cleaner ground a= nd/or location, as you say.
The noise at MiniWhip rised 20dB, so must get it
appart to keep the ear at MF/LF.
Yes, LF and MF stays important too! :-)
The power supply is a 12V transformer shared with the MiniWhip
Maybe this causes a ground loop which picks up the hum. Could explain why L= F/MF became worse as well.
Will test another one just for the VLF probe and with better filtering= .
Or try a battery in a first step and see the difference. A separate small t= ransformer supply is certainly a good decision.
The GND of the antenna is separated
from mains earth and there is an audio transformer to the PC soundcard=
FB.
BTW. What I'm getting from SL is one FFT file 112Kb size every hour as= Markus said
But how can I merge all the files of a 8h transmission like the one yo= ur are running now ?
Each file covers 8.9 hours. They are just overlapping so that you can selec= t the closest one (lowest start time offset). I don't know the exact settin= gs though. I would recommend to set the FFT center frequency to 8270.1 Hz.<= br>

Your signal in your grabber looks stronger than the previous transmiss= ions
It is the same antenna current though.

73, Stefan
--_000_579355A36AEE9D4FA555C45D556003AB8FDD90BFservigilantvigi_--