Return-Path: X-Spam-DCC: paranoid 1170; 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=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE 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 u1LBQFOe028726 for ; Sun, 21 Feb 2016 12:26:15 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aXS5l-0001zm-AS for rs_out_1@blacksheep.org; Sun, 21 Feb 2016 11:22:21 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aXS5k-0001zd-O8 for rsgb_lf_group@blacksheep.org; Sun, 21 Feb 2016 11:22:20 +0000 Received: from mail-wm0-f54.google.com ([74.125.82.54]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1aXS4g-0001h2-Lz for rsgb_lf_group@blacksheep.org; Sun, 21 Feb 2016 11:22:19 +0000 Received: by mail-wm0-f54.google.com with SMTP id a4so126581080wme.1 for ; Sun, 21 Feb 2016 03:20:59 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=tK5bCCpmRQuGejE51CWy8Wr2EQsrvgL+tIZ95RZqfow=; b=bTJ/mBuuUGAz7AanFgdekIX6ZFiedlv+rhIJaEDAnoZd2ywwAKU4j0BjlwRo4WpMWe aCkLrgr2mLzcl/8KJoKJXtLe060Gr/tAGglhye035jFLAnRmsrHFfesnGWapkxQRiM7E 1fBajVMkxiBN+MFqPE59+e9H9vsktz+hwAKZrsA6yrY0Hc4YBZgy3jTWncWE6uodGIPe Px+aN3IDx3GfqD/QCedrhs0vWBz4+EYrwvXGDcyD6Fg0RKxrJ0L7RoM7OZiTqAqx+Zv0 mgYkeEoi38vT5qDZV6waRLQ/Q+hUiKY8n8favFVr+Yz21H3qXKzsgvd9xt8Eek8Ax8Pv meAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=tK5bCCpmRQuGejE51CWy8Wr2EQsrvgL+tIZ95RZqfow=; b=UQVUSKNFrlzUIOr4TVfTmucTEik43fxKl2G41QUxTo+en3etyA08v1s7VEx2Ony/Kt Kl/b6CmzvKouCln7g34zOJgjPIV5ou6DeWNg4DNJJYLAfm/QGhsLERSree01Xf7rhD6s d7YyuHCgN65w78rkWcS+G1/UbMNsB2KHcIPYSm7nPUAwiMtRxdYB5op8tGN6QXFtTDMG YRkwNfz1x61jiK4NtLPkGiuSYeJ7tQNu2Vc8W73++2gCoQgytgJr055M8ziCCK9gZZAL UeApC2Yu5HoWbibsRw2UAYdYAd6mco9kq21BuQUlnj9pJz8TZk6wVjmIHEOSyVLCDIDU rCYw== X-Gm-Message-State: AG10YOSt4ldW3DH+5NlwNYQX2jj0OuReS6IRcHnbMP0CVqTj6+d+8EOVnd6RKaAtupCcjhk74UqZTSGbg2bx8A== MIME-Version: 1.0 X-Received: by 10.28.100.7 with SMTP id y7mr7117519wmb.87.1456053613204; Sun, 21 Feb 2016 03:20:13 -0800 (PST) Received: by 10.28.187.213 with HTTP; Sun, 21 Feb 2016 03:20:13 -0800 (PST) In-Reply-To: <1533051591.11599976.1456050163582.JavaMail.yahoo@mail.yahoo.com> References: <1533051591.11599976.1456050163582.JavaMail.yahoo.ref@mail.yahoo.com> <1533051591.11599976.1456050163582.JavaMail.yahoo@mail.yahoo.com> Date: Sun, 21 Feb 2016 11:20:13 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 92b6515a4252c45136e975e6745a1e0d Subject: Re: LF: Original 73kHz first. Content-Type: multipart/alternative; boundary=001a114b143063a062052c45e6f9 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 10.1.3.10 Status: RO X-Status: X-Keywords: X-UID: 6919 --001a114b143063a062052c45e6f9 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable As a rule of thumb, the near / far field transition is taken to be lambda/ 2.pi Where the reactive fields are down to below the level of the radiation . So for 137kHz that lies at 350m and for 475kHz at 100m For accurate measurements in the R field, you therefore need to be 2 - 4 times further away than those values give you. AFAIR, the magnetic field falls of faster than the Efield, but both faster than the radiation . 'jnt On 21 February 2016 at 10:22, M0FMT wrote: > Hi all > > Where does the distance for capaciive and or magnetic coupling end and th= e > main mode of electromagnetic radiation coupling begin? Is it defined? > > 73 es GL Pete M0FMT GQRP#15097.in IO91UX > > > Sent via my own personal Too-Way (two way) Earth Station to and from the > Eutelsat Ka-band satellite http://www.tooway.co.uk/ at > approximately 172 degrees Azimuth in the Clarke belt owing to BTs 19th > century cable technology inability to provide a good enough 21st century > broadband service. I agree for this message to be passed on to BT Plc at = 81 > Newgate Street, London EC1A 7AJ via the snoops at GCHQ Cheltenham, thank= s > for your cooperation it is appreciated. > > -------------------------------------------- > On Sat, 20/2/16, F6CNI - Andy - JN19QB wrote: > > Subject: Re: LF: Original 73kHz first. > To: rsgb_lf_group@blacksheep.org > Date: Saturday, 20 February, 2016, 7:54 > > > > > Hello Andy. > > Not about the first claimed 73kHz QSO, but just for > info > : > > the first time I heard Peter G3LDO on 73.4 kHz normal > CW ( > 338 km ) was around november / december 1996. Later, I had > my first xband QSO > 73.3 / 3.570 kHz with him 28 march 1998. I received his nice > QSL for this event. > It was, I think, the only all time QSO normal CW xband from > UK to outside UK. > But Peter and probably others UK stations had also some > =E2=80=9CDX=E2=80=9D QRSS QSO xband 73 / > 137 : one day ( I do not remember the date ) I see Peter in > QSO QRSS3 with > HB9ASB... > > 73 de Andy F6CNI. > > > From: > Andy > Talbot > > Sent: Friday, > February 19, 2016 11:40 PM > To: > rsgb_lf_group@blacksheep.org > ; rsgb_lf_group@yahoogroups.co.uk > > > Subject: LF: Original > 73kHz first. > > > Can anyone remember what the first claimed > 73kHz QSO was > . I seem to remember it was a few tens of metres across a > car park, > probably in 1996 > > (Strictly, that was a capacitor not radiation, > but...) > > I'm giving a talk on LF/MF in a couple of weeks, > and want to get the > timeline right. > > Andy > G4JNT > > --001a114b143063a062052c45e6f9 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
As a rule of thumb, the near / far field transition is tak= en to be lambda/ 2.pi =C2=A0 Where the reactive fields are down to below th= e level of the radiation .

So for 137kHz that lies = at 350m =C2=A0 =C2=A0 and for =C2=A0475kHz at 100m

For accurate measurements in the R field, you therefore need to be 2 - 4 t= imes further away than those values give you.

AFAI= R, the magnetic field falls of faster than the Efield, but both faster than= the radiation .

'jnt



On 21 February 2016 at 10:22, M0FMT <m0fmt@yahoo.co.uk> wrote:
Hi all

Where does the distance for capaciive and or magnetic coupling end and the = main mode of electromagnetic radiation coupling begin? Is it defined?

73 es GL Pete M0FMT GQRP#15097.in IO91UX


Sent via my own personal Too-Way (two way) Earth Station to and from=C2=A0t= he Eutelsat Ka-band satellite=C2=A0 http://www.tooway.co.uk/ =C2=A0at ap= proximately=C2=A0172 degrees Azimuth in the Clarke belt owing to BTs 19th c= entury cable technology=C2=A0inability to provide a good enough 21st centur= y broadband service. I agree for this message to be passed on to BT Plc at = 81 Newgate Street, London EC1A 7AJ=C2=A0 via the snoops at GCHQ Cheltenham,= thanks for=C2=A0your cooperation it is appreciated.

--------------------------------------------
On Sat, 20/2/16, F6CNI - Andy - JN19QB <f6cni@orange.fr> wrote:

=C2=A0Subject: Re: LF: Original 73kHz first.
=C2=A0To: rsgb_lf_group@bla= cksheep.org
=C2=A0Date: Saturday, 20 February, 2016, 7:54




=C2=A0Hello Andy.
=C2=A0=C2=A0
=C2=A0Not about the first claimed 73kHz QSO, but just for
=C2=A0info
=C2=A0:
=C2=A0=C2=A0
=C2=A0the first time I heard Peter G3LDO on 73.4 kHz normal
=C2=A0CW (
=C2=A0338 km ) was around november / december 1996. Later, I had
=C2=A0my first xband QSO
=C2=A073.3 / 3.570 kHz with him 28 march 1998. I received his nice
=C2=A0QSL for this event.
=C2=A0It was, I think, the only all time QSO normal CW xband from
=C2=A0UK to outside UK.
=C2=A0But Peter and probably others UK stations had also some
=C2=A0=E2=80=9CDX=E2=80=9D QRSS QSO xband 73 /
=C2=A0137 : one day ( I do not remember the date ) I see Peter in
=C2=A0QSO QRSS3 with
=C2=A0HB9ASB...
=C2=A0=C2=A0
=C2=A073 de Andy F6CNI.

=C2=A0=C2=A0
=C2=A0From:
=C2=A0Andy
=C2=A0Talbot

=C2=A0Sent: Friday,
=C2=A0February 19, 2016 11:40 PM
=C2=A0To:
=C2=A0rsgb_lf_group@blacksh= eep.org
=C2=A0; rsgb_lf_group@ya= hoogroups.co.uk


=C2=A0Subject: LF: Original
=C2=A073kHz first.
=C2=A0=C2=A0

=C2=A0Can anyone remember what the first claimed
=C2=A073kHz QSO=C2=A0 was
=C2=A0.=C2=A0 I seem to remember it was a few tens of metres across a
=C2=A0car park,
=C2=A0probably in 1996

=C2=A0(Strictly, that was a capacitor not radiation,
=C2=A0but...)
=C2=A0=C2=A0
=C2=A0I'm giving a talk on LF/MF in a couple of weeks,
=C2=A0and want to get the
=C2=A0timeline right.
=C2=A0=C2=A0
=C2=A0Andy=C2=A0
=C2=A0G4JNT


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