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=-1.9 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_40_50,HTML_MESSAGE,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 u2K8nDh8030032 for ; Sun, 20 Mar 2016 09:49:14 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ahYzx-0005BC-IB for rs_out_1@blacksheep.org; Sun, 20 Mar 2016 08:46:09 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ahYzx-0005B3-4R for rsgb_lf_group@blacksheep.org; Sun, 20 Mar 2016 08:46:09 +0000 Received: from nm12-vm4.bullet.mail.ir2.yahoo.com ([212.82.96.174]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1ahYzv-00041J-47 for rsgb_lf_group@blacksheep.org; Sun, 20 Mar 2016 08:46:08 +0000 X-DKIM-Result: Domain=yahoo.co.uk Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s2048; t=1458463565; bh=D8KYOc6407q6j52YyW79CyWwls/qH9bQZa4+0zlaJBs=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=W4U9Djj6K5mrYdAWm0TyBM3ZuLw/aeEOX1GQ4O7Wb7iuF3hLXXaOAVA3ABhlII12t5qhsSPD+mOXJcIPXT7kqsL05maK1viZcx1nge86LdCMCUyzeNK99kceZPKMNaXpFrTV2rOgTESFVOpTJf/cjKMwH2Th/eyw8jegpolenOaskoAakh1nsdXjcmVDE3dw8QoKO+1ytQSu4X/gt9TOYTeNEEBRzjegSybLHqtp/+sPtfFV+UGew27XSxsFYMN1M48n/29iiJUjRLWwzkNgqFa8LjOhVtiXKqTgv7tTElqymsIu9q+C9mIwYx+Vdpcj7jNwAV9pYU6pegpe2YM50Q== Received: from [212.82.98.56] by nm12.bullet.mail.ir2.yahoo.com with NNFMP; 20 Mar 2016 08:46:05 -0000 Received: from [212.82.98.70] by tm9.bullet.mail.ir2.yahoo.com with NNFMP; 20 Mar 2016 08:46:05 -0000 Received: from [127.0.0.1] by omp1007.mail.ir2.yahoo.com with NNFMP; 20 Mar 2016 08:46:05 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 896050.27606.bm@omp1007.mail.ir2.yahoo.com X-YMail-OSG: gcoZIIAVM1lVIWjwOKGnRZqNaCSw8qlinGD0BPAwtGf47rJQmik8Om9maiKgwsS wPDyZcdmO8cOUAIilV4d5HHT5_V_CehpHd39DHhCZsUkAxQ8G6MoaS.JsQjw37XLYmXTipKgT5.Z Z0fJ03FnSqyUShO6IsqWUKfngjWQAyfjBi17q8CCQgcVnp6ni2eNqExvZr3FJL.0t_nh6Q1YVgnU eLvrXXP5OCc7fpsskXK4wYJl4vu1i.WBukp1i.UtAnCvM2q5YjbUDg5_zIiD0Zlu1xp57hfmv5io Vtc91s1OZHu7ScdOO8lLY.xBTNUT2BQAnN8L2cjdVcW9sVnALOndegyPGdGsC7q9PDvkZeX9hapr mQjhU5V8EIEhMqhRSR7E7pPkLtxVV1td6OvgBeumhR4eTlsIaZEGcaPubkWdUjqx.hWfQox_uzRW CLOj3uINNlPHjJx1VcOLHRermR_1r94az4WXog6oYz_AdfrUtE9nk0EwAHIuYc8g2ZFgDaLaB.Fa 8wg8qucKNl68.kIrGcvY5S4Zdvl7Ej60- Received: by 217.12.9.10; Sun, 20 Mar 2016 08:46:05 +0000 Date: Sun, 20 Mar 2016 08:45:48 +0000 (UTC) From: David Hine To: "rsgb_lf_group@blacksheep.org" Message-ID: <932469599.2665382.1458463549293.JavaMail.yahoo@mail.yahoo.com> In-Reply-To: <56EE53C4.3010801@abelian.org> References: <56EE53C4.3010801@abelian.org> MIME-Version: 1.0 X-Scan-Signature: 617a5faed955112e448650f4d003a84d Subject: Re: LF: EbNaut from Todmorden Content-Type: multipart/alternative; boundary="----=_Part_2665381_1640350458.1458463549289" 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: 7427 ------=_Part_2665381_1640350458.1458463549289 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi Paul. Interesting and I would like to know if you have any success with = earth mode once the amplifier shutdowns have bee solved. (Some in field rec= eiving may be interesting).=C2=A0It may be an unfortunate choice of the num= ber of transformer primary turns that=C2=A0happens to be resonating as a se= ries tuned circuit at 8 kHz and appearing as a short circuit to the amplifi= er? -add some more turns?=C2=A0-just a guess. Roger's ELF work is excellent= and should be always used to 'get the feel' of ground communications. To h= ave any real chance of success, megawatts are necessary, but this is not po= ssible for most researchers. With very kind regards, Dave. From: Paul Nicholson To: rsgb_lf_group@blacksheep.org=20 Sent: Sunday, 20 March 2016, 7:39 Subject: Re: LF: EbNaut from Todmorden =20 I found what I was looking for in Roger Lapthorn's notes on earth mode at =C2=A0 https://sites.google.com/site/sub9khz/earthmode where he mentions that licencing is not required.=C2=A0 However he is talking about earth mode where comms are via ground currents and there is no intended use of far field radiation. This is in contrast to an earth antenna where the ground current forms the lower leg of a vertical loop, such as is used by the military at ELF. Last night I fired up the amplifier and through the transformer was able to put about 600V RMS onto the wire, so about a kW into 380 ohms.=C2=A0 The transformer worked very well but for some reason the amplifier kept wanting to do a thermal shutdown which is odd considering its 5kW average power rating. It's supposed to do 2.5kW average into a 1 ohm load. The test was at 8270.01 Hz but not even the faintest trace showed up on Gary G4WGT's spectrogram at 35km distance.=C2=A0 Not surprising really, the ground around here is quite unsuitable as an earth loop: a metre or two of wet soil over the sandstone bedrock, the return current is not going to go deep. The transformer appears quite good at 8270 Hz and looks like it might work well at coupling power into the base of a VLF loading coil. The ground antenna has so far qualified itself as a nice high power dummy load.=C2=A0 This evening I'll play a little more with it just to understand what the amplifier is doing but I don't think I'll continue much more with these earth experiments. David Hine wrote: > take care as the mains 'earth' Yes.=C2=A0 Several years ago I experienced just that.=C2=A0 I found, I thin= k, about 40V between the domestic earth and a VLF antenna earth. Eventually I traced it to an electrical fault in a neighbour's tractor shed.=C2=A0 The entire domestic ground of our little cluster of farms was at significant mains potential relative to a more distant earth ground.=C2=A0 This might have gone unnoticed had I not been setting up a remote rx with its own ground.=C2=A0 During a storm, nearby lightning could easily produce very large transient voltages between domestic ground and the ground of a remote antenna. I always disconnect everything on the approach of a storm. Right now, about 1.5V RMS at 50Hz between the ground 500m away and the house ground. It isn't unknown for farmers to run a single wire carrying live out to a distant shed with the return current via the ground.=C2=A0 If anyone was doing that near here I would soon know about it! -- Paul Nicholson -- ------=_Part_2665381_1640350458.1458463549289 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Hi Paul. Int= eresting and I would like to know if you have any success with earth mode o= nce the amplifier shutdowns have bee solved. (Some in field receiving may b= e interesting). It may be an unfortunate choice of the number of trans= former primary turns that happens to be resonating as a series tuned c= ircuit at 8 kHz and appearing as a short circuit to the amplifier? -add som= e more turns? -just a guess. Roger's ELF work is excellent and should = be always used to 'get the feel' of ground communications. To have any real= chance of success, megawatts are necessary, but this is not possible for m= ost researchers. With very kind regards, Dave.


From: Paul Nicholson <vlf0403@abelian.org>
To: rsgb_lf_group@blacksheep.org
Sent: Sunday, 20 March 2016, 7:39=
Subject: Re: LF: EbNa= ut from Todmorden


I found what I = was looking for in Roger Lapthorn's notes on
earth mode a= t

  https://sites.google.com/site/sub9khz/eart= hmode

where he mentions that licen= cing is not required.  However he
is talking about e= arth mode where comms are via ground currents
and there i= s no intended use of far field radiation.

This is in contrast to an earth antenna where the ground
current forms the lower leg of a vertical loop, such as is
used by the military at ELF.

Las= t night I fired up the amplifier and through the transformer
was able to put about 600V RMS onto the wire, so about a
kW into 380 ohms.  The transformer worked very well but
for some reason the amplifier kept wanting to do a thermal
shutdown which is odd considering its 5kW average power rating.=
It's supposed to do 2.5kW average into a 1 ohm load.

The test was at 8270.01 Hz but not even t= he faintest trace
showed up on Gary G4WGT's spectrogram a= t 35km distance.  Not
surprising really, the ground = around here is quite unsuitable
as an earth loop: a metre= or two of wet soil over the sandstone
bedrock, the retur= n current is not going to go deep.

The= transformer appears quite good at 8270 Hz and looks like
it might work well at coupling power into the base of a VLF
loading coil.

The ground antenna h= as so far qualified itself as a nice high
power dummy loa= d.  This evening I'll play a little more
with it ju= st to understand what the amplifier is doing but I
don't = think I'll continue much more with these earth experiments.

David Hine wrote:
> take care a= s the mains 'earth'

Yes.  Several= years ago I experienced just that.  I found, I think,
about 40V between the domestic earth and a VLF antenna earth.
Eventually I traced it to an electrical fault in a neighbour'stractor shed.  The entire domestic ground of our littl= e
cluster of farms was at significant mains potential rel= ative to
a more distant earth ground.  This might ha= ve gone unnoticed had I
not been setting up a remote rx w= ith its own ground.  During a
storm, nearby lightnin= g could easily produce very large transient
voltages betw= een domestic ground and the ground of a remote antenna.
I= always disconnect everything on the approach of a storm.

Right now, about 1.5V RMS at 50Hz between the ground 50= 0m away and
the house ground.

It isn't unknown for farmers to run a single wire carrying live o= ut
to a distant shed with the return current via the grou= nd.  If anyone
was doing that near here I would soon= know about it!


--
Paul Nicholson
--



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