Return-Path: Received: from mtain-ma11.r1000.mx.aol.com (mtain-ma11.r1000.mx.aol.com [172.29.96.19]) by air-de01.mail.aol.com (v129.4) with ESMTP id MAILINDE014-5ea54c436ff7253; Sun, 18 Jul 2010 17:19:51 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma11.r1000.mx.aol.com (Internet Inbound) with ESMTP id 014A8380000A4; Sun, 18 Jul 2010 17:19:49 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OabG6-0004lA-Ir for rs_out_1@blacksheep.org; Sun, 18 Jul 2010 22:18:50 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OabG5-0004l1-QF for rsgb_lf_group@blacksheep.org; Sun, 18 Jul 2010 22:18:49 +0100 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OabG3-0004yi-K3 for rsgb_lf_group@blacksheep.org; Sun, 18 Jul 2010 22:18:49 +0100 Received: by bwz13 with SMTP id 13so2424836bwz.16 for ; Sun, 18 Jul 2010 14:18:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=43yDJe7jdQeL8nd4a8b/qr3Vt17uH8uhb/dtKZqpr+4=; b=gJNRN02M+fIAcmBUKPCRs0Ivm8LNE0IKKxozwUTFEu1G5KouXfaJRBuUu+Q3qAlbv4 9CpTnO928xD82lMGyRS83s7bmlAF2Fo+cXkvRefg5Rq1HTrEEaevVEpbgbMdgBOuonpM 0xmFmEDRjO5tK9d75DaKeKlqucYgpbep1zFTg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=j2oA4hpMaxcwaIL9PjIF9bTypMXg2U4DqOHFg5Sabd0u6itUMPLH7NyvKYDlj5vjXb QlUi8tVCQSnMX5CndlPHyJUBY26OW3g7jmNNVxAMqN3cQMRUDt0pOeplCVJG6WM1SrGP ZKiDx6NhLt2sSLfwrPBCF7co2MJujSff4UYhI= MIME-Version: 1.0 Received: by 10.204.163.133 with SMTP id a5mr3314779bky.6.1279487925251; Sun, 18 Jul 2010 14:18:45 -0700 (PDT) Received: by 10.204.122.148 with HTTP; Sun, 18 Jul 2010 14:18:45 -0700 (PDT) In-Reply-To: <001101cb26bb$48ea5e10$4001a8c0@lark> References: <001101cb26bb$48ea5e10$4001a8c0@lark> Date: Sun, 18 Jul 2010 22:18:45 +0100 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: 136.96kHz testing Content-Type: multipart/alternative; boundary=000325558c9e476f34048bafff48 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=BE_AMAZED,HTML_MESSAGE autolearn=no version=2.63 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-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d229.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60134c436ff565c3 X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --000325558c9e476f34048bafff48 Content-Type: text/plain; charset=ISO-8859-1 Alan, Yes, that ties up with the signal being stronger with the E-field probe held above my head. Agreed, that lambda/2pi is around 350m, so I'm only just exiting the near field region. Tomorrow I may do some QRSS3 tests locally to see if I can see the QRPp 136kHz signal a few kms away with E-field probe and FT817. When I get properly started on the band - with a "real" (up in the air) antenna and some more power - I'd appreciate some reports from you Alan. You are indeed at a useful distance from me. It may take me some time to get things together but 136kHz is a project that is slowly gathering some momentum here now. With HF being nothing to get excited about at the moment, I think 136kHz will be worth a try. 73s Roger G3XBM On 18 July 2010 21:52, Alan Melia wrote: > Hi Roger dont forget the e-field probe has a sensitivity which is related > to > its height not the length of the whip. If you are holding a conducting case > the effective height is say 2m , at carrying heigh say 1m the signal > collected will only be half as strong. You are barely out of the near field > at 400m but getting close. > > Unfortunately I dont have a an LF receiver and aerial connected up at the > moment, I will have to sort that out because at 50 miles (ish) I would be > an > interesting distance for you.. > > Alan G3NYK > > ----- Original Message ----- > From: "Roger Lapthorn" > To: > Sent: Sunday, July 18, 2010 8:50 PM > Subject: Re: LF: 136.96kHz testing > > > > The measured power out from the PA is actually 250mW going into the earth > > electrodes. As a test I connected a PA0RDT designed active > > antennarun > > from a 9V PP3 battery and connected this to the (deaf at 136kHz) FT817 > > and went for my walk across the fields. The signal was copyable (not > strong) > > at 0.4km with 10wpm CW. Signal was stronger if I held the E-field probe > > above my head. > > > > Those of you like Mal who work multiple continents on the band will thing > > this is nothing, but it gives me a starting point from which to > > progressively improve my system. I'm just amazed that 250mW into earth > > electrodes 20m apart can be heard Q5 at 0.4km with a 19 inch whip > handheld. > > > > More fun next week... > > > > 73s > > Roger G3XBM > > > > On 18 July 2010 17:14, Roger Lapthorn wrote: > > > > > *This is the very beginning of my journey onto 136kHz.... > > > > > > *For anyone very *very* close to Burwell, Cambs, JO02DG, I'm putting a > QRP > > > 10wpm keyer-generated CW message (later to be changed to QRSS3) out on > > > 136.96kHz CW into my earth electrode antenna. Power from the TX is > about > > > 500mW, so ERP is just a few microwatts at most. > > > > > > I'd appreciate reports, but be amazed to get any until I start to run > some > > > more power into a real antenna. > > > > > > 73s > > > Roger G3XBM > > > > > > > > > -- > > > http://g3xbm-qrp.blogspot.com/ > > > http://www.g3xbm.co.uk > > > http://www.youtube.com/user/g3xbm > > > G3XBM GQRP 1678 ISWL G11088 > > > > > > > > > > > -- > > http://g3xbm-qrp.blogspot.com/ > > http://www.g3xbm.co.uk > > http://www.youtube.com/user/g3xbm > > G3XBM GQRP 1678 ISWL G11088 > > > > > -- http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --000325558c9e476f34048bafff48 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Alan,

Yes, that ties up with the signal being stronger with the E-f= ield probe held above my head. Agreed, that lambda/2pi is around 350m, so= I'm only just exiting the near field region. Tomorrow I may do some= QRSS3 tests locally to see if I can see the QRPp 136kHz signal a few kms= away with E-field probe and FT817.

When I get properly started on the band - with a "real" (up= in the air) antenna and some more power - I'd appreciate some reports= from you Alan. You are indeed at a useful distance from me.

It ma= y take me some time to get things together but 136kHz is a project that is= slowly gathering some momentum here now. With HF being nothing to get exc= ited about at the moment, I think 136kHz will be worth a try.

73s
Roger G3XBM



On 18 Jul= y 2010 21:52, Alan Melia <alan.melia@btinternet.com> wrote:
Hi Roger dont forget the e-field probe has a sensitivity which is related= to
its height not the length of the whip. If you are holding a conducting cas= e
the effective height is say 2m , at carrying heigh say 1m the signal
collected will only be half as strong. You are barely out of the near fiel= d
at 400m but getting close.

Unfortunately I dont have a an LF receiver and aerial connected up at the<= br> moment, I will have to sort that out because at 50 miles (ish) I would be= an
interesting distance for you..

Alan G3NYK

----- Original Message -----
From: "Roger Lapthorn" <rogerlapthorn@gmail.com>
To: <rsgb_lf_group@blac= ksheep.org>
Sent: Sunday, July 18, 2010 8:50 PM
Subject: Re: LF: 136.96kHz testing


> The measured power out from the PA is actuall= y 250mW going into the earth
> electrodes. As a test I connected a PA0RDT designed active
> antenna<http:= //carc.org.uk//carc_ftp/G3GRO-PA0RDT-Active_Ant.pdf>run
> from a 9V PP3 battery and connected this to the (deaf at 136kHz) FT81= 7
> and went for my walk across the fields. The signal was copyable (not<= br> strong)
> at 0.4km with 10wpm CW. Signal was stronger if I held the E-field pro= be
> above my head.
>
> Those of you like Mal who work multiple continents on the band will= thing
> this is nothing, but it gives me a starting point from which to
> progressively improve my system. I'm just amazed that 250mW into= earth
> electrodes 20m apart can be heard Q5 at 0.4km with a 19 inch whip
handheld.
>
> More fun next week...
>
> 73s
> Roger G3XBM
>
> On 18 July 2010 17:14, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
>
> > *This is the very beginning of my journey onto 136kHz....
> >
> > *For anyone very *very* close to Burwell, Cambs, JO02DG, I'm= putting a
QRP
> > 10wpm keyer-generated CW message (later to be changed to QRSS3)= out on
> > 136.96kHz CW into my earth electrode antenna. Power from the TX= is about
> > 500mW, so ERP is just a few microwatts at most.
> >
> > I'd appreciate reports, but be amazed to get any until I sta= rt to run
some
> > more power into a real antenna.
> >
> > 73s
> > Roger G3XBM
> >
> >
> > --
> > htt= p://g3xbm-qrp.blogspot.com/
> > http://www.= g3xbm.co.uk
> > = http://www.youtube.com/user/g3xbm
> > G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
> >
>
>
>
> --
> http://g= 3xbm-qrp.blogspot.com/
> http://www.g3xbm= .co.uk
> http:= //www.youtube.com/user/g3xbm
> G3XBM =A0 =A0GQRP 1678 =A0 =A0 =A0ISWL G11088
>





--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm G3XBM=A0 =A0 GQRP 1678=A0 =A0 =A0 ISWL G11088
--000325558c9e476f34048bafff48--