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: x.dcc-servers: mailn 104; 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 v4CFnp3r015307 for ; Fri, 12 May 2017 17:49:53 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1d9Clv-0007Kx-Sm for rs_out_1@blacksheep.org; Fri, 12 May 2017 16:46:27 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1d9Cls-0007Kg-7Y for rsgb_lf_group@blacksheep.org; Fri, 12 May 2017 16:46:24 +0100 Received: from gmy2-mh808.smtproutes.com ([94.186.192.137]) by relay1.thorcom.net with esmtp (Exim 4.89) (envelope-from ) id 1d9Clo-00030e-RF for rsgb_lf_group@blacksheep.org; Fri, 12 May 2017 16:46:22 +0100 X-Katharion-ID: 1494603965.40480.gmy2-mh808 Received: from servigilant.vigilant.es ([85.60.35.36]) by gmy2-mh808.smtproutes.com [(94.186.192.137)] with ESMTP via TCP (TLSv1/TLS_RSA_WITH_AES_256_CBC_SHA); 12 May 2017 15:46:05 +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; Fri, 12 May 2017 17:45:21 +0200 From: =?iso-8859-1?Q?VIGILANT_Luis_Fern=E1ndez?= To: "rsgb_lf_group@blacksheep.org" Thread-Topic: LF: Some improvements in VLF Rx Thread-Index: AQHSx9nZWsQEGQ1Vj0+K4FRSFr5O6aHvBxsAgAFnWICAABQ0gIAAWr8g Date: Fri, 12 May 2017 15:45:21 +0000 Message-ID: <579355A36AEE9D4FA555C45D556003AB8FDDC353@servigilant.vigilant.local> In-Reply-To: <5915A837.2030707@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: 350b42a0642244046701ed1a68bf48aa Subject: RE: LF: Some improvements in VLF Rx Content-Type: multipart/alternative; boundary="_000_579355A36AEE9D4FA555C45D556003AB8FDDC353servigilantvigi_" 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: 11680 --_000_579355A36AEE9D4FA555C45D556003AB8FDDC353servigilantvigi_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thank you Stefan The SL instance is updated with the modified USR file. Non stopped, so you = can see the difference https://ea5dom.ure.es/grabber/index.html 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: viernes, 12 de mayo de 2017 14:19 Para: rsgb_lf_group@blacksheep.org Asunto: Re: LF: Some improvements in VLF Rx Hi Luis, Am 12.05.2017 11:43, schrieb VIGILANT Luis Fern=E1ndez: I can add an SMD ferrite bead (0805) in the gate Worth to try. The voltage in the coax down in the shack after the 390R is 6V. Power suppl= y is 14V. So there must be some current trought the FET Will measure the current Yes it is 8V/390R =3D 20 mA. That's a bit much. You could increase that res= istor to get about 10 mA, maybe 680 Ohm is a good value. This is the picture of the 5m mast, which is metal. The last section is a P= VC pipe which holds the MiniWhip. The VLF probe is hold in a plastic box containing the FET and attached to the metal mast using a metal adaptor. So= it is quite close to the metal mast, which can provide high capacity ? Probe lenght is 1m https://dl.dropboxusercontent.com/u/7162072/fotos%20varias/MF/IMG_20170430_= 125017.jpg Looks like a good place. The 1m probe should be fine. The capacity is given= by the probe, about 5 pF/m is the rule. 1m should be fine when the antenna= is at this location. The only problem seems to be the contaminated ground. You just need to expe= riment and find the best results. Maybe it helps to isolate the probe ground from the mast and feed the cable= down to the ground where it has its own earth and an isolation transformer= between the TV cable and soundcard... You know... Yes. Using the battery there was no difference, once the ground loop was re= moved. Sounds good! That will be fine ! File is here https://dl.dropboxusercontent.com/u/7162072/fotos%20varias/MF/VLF_Soundcard= _32KHz.USR Modified file in attachment. Will try also a twisted pair instead of the coax There will be no improvement. I would stay at coax. Good luck for getting a cleaner background... 73, Stefan --_000_579355A36AEE9D4FA555C45D556003AB8FDDC353servigilantvigi_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thank you Stefan
 
The SL instance is updated with t= he modified USR file. Non stopped, so you can see the difference
 
73 de Luis
EA5DOM

De: owner-rsgb_lf_group@blacksheep.= org [mailto:owner-rsgb_lf_group@blacksheep.org] En nombre de DK7FC
Enviado el: viernes, 12 de mayo de 2017 14:19
Para: rsgb_lf_group@blacksheep.org
Asunto: Re: LF: Some improvements in VLF Rx

Hi Luis,

Am 12.05.2017 11:43, schrieb VIGILANT Luis Fern=E1ndez:
 
I can add an SMD ferrite bead (0805) in the gate
Worth to try.

The voltage in the coax down in the shack after the 390R is = 6V. Power supply is 14V. So there must be some current trought the FET
Will measure the current
Yes it is 8V/390R =3D 20 mA. That's a bit much. You could increase that res= istor to get about 10 mA, maybe 680 Ohm is a good value.

This is the picture of the 5m mast, which is metal. The last sect= ion is a PVC pipe which holds the MiniWhip. The VLF probe is hold in a plas= tic box
containing the FET and attached to the metal mast using a me= tal adaptor. So it is quite close to the metal mast, which can provide high= capacity ?
Probe lenght is 1m
Looks like a good place. The 1m probe should be fine. The capacity is given= by the probe, about 5 pF/m is the rule. 1m should be fine when the antenna= is at this location.
The only problem seems to be the contaminated ground. You just need to expe= riment and find the best results.
Maybe it helps to isolate the probe ground from the mast and feed the cable= down to the ground where it has its own earth and an isolation transformer= between the TV cable and soundcard... You know...

Yes. Using the battery there was no difference, once the ground = loop was removed.
Sounds good!

That will be fine ! File is here
Modified file in attachment.
Will try also a twisted pair instead of the coax
There will be no improvement. I would stay at coax.

Good luck for getting a cleaner background...

73, Stefan --_000_579355A36AEE9D4FA555C45D556003AB8FDDC353servigilantvigi_--