Return-Path: Received: from mtain-mb05.r1000.mx.aol.com (mtain-mb05.r1000.mx.aol.com [172.29.96.25]) by air-ma09.mail.aol.com (v129.4) with ESMTP id MAILINMA091-b5344d07a6322eb; Tue, 14 Dec 2010 12:15:30 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mb05.r1000.mx.aol.com (Internet Inbound) with ESMTP id E71CC380002D5; Tue, 14 Dec 2010 12:15:24 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PSYST-00089h-W4 for rs_out_1@blacksheep.org; Tue, 14 Dec 2010 17:14:37 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PSYST-00089Y-Cl for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 17:14:37 +0000 Received: from mail-gy0-f171.google.com ([209.85.160.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PSYSR-0005HR-2X for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 17:14:37 +0000 Received: by gyg13 with SMTP id 13so471275gyg.16 for ; Tue, 14 Dec 2010 09:14:28 -0800 (PST) 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=oExbHR0kUd2OdUTDuxN17u03Q3LRs5vQ8b+3qQh6WnQ=; b=a7xEfmgGpfQGs4s6QCMQUUUbkqiP8M/U35RD+c/moiGi8yK24DZdqAhM7Hyj2TPjPD YlewE/ymF6YrCX972kodfLLfSuNYOXqq9VdFcfqFf+QJj91kbqgW/QutD1Q2Xj9ZQ84g zdFLeIjdvu9aAWmfCjESzbFwwp5cqwrd3+BTo= 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=R/RICzGkR5BW40ZknRTzfaZwax0poRRDe6IuZqovt5Bbkd8trD2MyxMx+bBibM7w0P /LAxm9SiUPKVubrlmdp7roI+9iqRhyStVSPcjlKMTedPHFX4cmd2us8126GNt4T9lE3Z y64h7Y6NP5znVZtQPqtmognWWmEoxp3TAHZHs= MIME-Version: 1.0 Received: by 10.42.172.135 with SMTP id n7mr4616112icz.117.1292346868370; Tue, 14 Dec 2010 09:14:28 -0800 (PST) Received: by 10.42.239.71 with HTTP; Tue, 14 Dec 2010 09:14:28 -0800 (PST) In-Reply-To: References: <80E0204D3E534137903FE0B8E499597F@IBM7FFA209F07C> <4D0783FC.3090107@iup.uni-heidelberg.de> Date: Tue, 14 Dec 2010 17:14:28 +0000 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: Earth Electrodes Content-Type: multipart/alternative; boundary=90e6ba6137d0040e89049761f467 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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-d304.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60194d07a62c37bf X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --90e6ba6137d0040e89049761f467 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Andy, Surely two synchronised TX systems can only increase ERP by 3dB maximum? ...or am I missing something? Yes, 600m baseline is similar to Sanguine *pro rata* with frequency and th= at system got a megawatt TX output signal around the world and to a considerable depth in the ocean with 100% reliability. Luckily we don't ne= ed to reach the ocean floors, so our ERP can be somewhat lower (!). A 600m baseline would not be that difficult to arrange for a portable test out in the countryside or across National Trust land or woodlands. 73s Roger G3XBM On 14 December 2010 16:54, Andy Talbot wrote: > Google "Project Sanguine" > > http://www.fas.org/nuke/guide/usa/c3i/fs_clam_lake_elf2003.pdf > suggests more than 60km of cable used at 76Hz, so pro-rata not dissimili= ar > to 600m earth spacing at 9kHz > > However, they do use two synchronised transmitters, so the effective > baseline becomes far greater. > > Now, how abot that for 8970Hz. Two stattion using low cost simple GPSD= Os > and similar DDS / synthesizers can reasonably guarantee their respective > frequencies accuracy to 10^-9 short term At 10kHz (to keep numbers simp= le), > that is a differnece freq of no more than 10^-5, or 100000 seconds, or= one > cycle in just over a day. And over this period, GPS derived sources wil= l > average out as spot-on. > > So, for low cost simple amateur coherent wide spaced VLF signalling > frequency is not an issue. SIgnal element timing can be synchronised= to > sub microsecnds, again using GPS timing. > > Maybe worth thinking about. Reading the posts so far, 'JNT interest co= uld > be rekindled, so may yet apply for my NoV - although with a total house= plot > of only some 25 x 7 metres, there not really any scope for Tx antennas > unless I use ground wires looping over the garden wall into and along th= e > road at the back > > Andy > www.g4jnt.com > > > > > On 14 December 2010 16:27, Chris wrote: > >> HiStefan, >> Yes, but 600m is VERY long! The wire even laying on the ground I would >> expect to radiate quite well at 137 with that length! And how many watt= s?? >> ERP?? >> I am sure 8970 would do well *through the ground* at the sort of powers >> being spoken about. Probably ideal for submarines, as Roger says! >> Vy 73, Chris, G4AYT. >> >> ----- Original Message ----- >> *From:* Stefan Sch=E4fer >> *To:* rsgb_lf_group@blacksheep.org >> *Sent:* Tuesday, December 14, 2010 2:49 PM >> *Subject:* Re: LF: Earth Electrodes >> >> Hi Chris, >> >> But how do you explain that i have crossed 49.6 km with a 600m spaced >> earth electrode antenna on 8970 Hz? It was rather summer time than wint= her >> (regarding QRN)! With the same antenna, my 137 kHz signal was seen 20= dB >> above noise near Paris in DFCW-3!????? >> >> 73, Stefan >> >> >> Am 14.12.2010 15:15, schrieb Chris: >> >> Hi Mal, >> Yes, that is what I had concluded years ago. No harm in trying though! >> Further to your previous e-mail to LF, looks to me like beacons are now >> becoming the norm on 136/7kHz band and below. I have no problem with th= at >> personally, indeed, I think it preferable to a QSO taking forever! I wo= ud >> like to see full idents though, no matter how slow. >> Vy 73, >> Chris, G4AYT. >> >> > --=20 g3xbm-qrp.blogspot.com/ www.g3xbm.co.uk www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --90e6ba6137d0040e89049761f467 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Andy,

Surely two synchronised TX systems can only increase ERP by= 3dB maximum? ...or am I missing something?

Yes, 600m baseline is= similar to Sanguine pro rata with frequency and that system got a= megawatt TX output signal around the world and to a considerable depth in= the ocean with 100% reliability. Luckily we don't need to reach the= ocean floors, so our ERP can be somewhat lower (!). A 600m baseline would= not be that difficult to arrange for a portable test out in the countrysi= de or across National Trust land or woodlands.

73s
Roger G3XBM

On 14 December 20= 10 16:54, Andy Talbot <andy.g4jnt@gmail.com> wrote:
Google "Project Sanguine"
=A0
=A0 http://www.fas.org/nuke/guide/usa/c3i/fs_clam_= lake_elf2003.pdf=A0=A0 suggests more than=A060km of cable used at 76Hz= , so pro-rata not dissimiliar to 600m earth spacing at 9kHz
=A0
However, they do use two synchronised transmitters, so the effective= baseline becomes far greater.=A0=A0
=A0
Now, how abot that for 8970Hz.=A0=A0 Two stattion using low cost simp= le GPSDOs and similar DDS / synthesizers can reasonably guarantee their re= spective frequencies=A0accuracy to=A010^-9=A0short term=A0 At 10kHz (to ke= ep numbers=A0simple), that is a differnece freq of no more than 10^-5, or= 100000 seconds, or one cycle in just over a day.=A0 And over this period,= GPS derived sources will average out as spot-on.
=A0
So, for low cost simple amateur coherent wide spaced VLF signalling= frequency is not an issue.=A0=A0=A0 SIgnal element timing can be synchron= ised to sub microsecnds, again using GPS timing.
=A0
Maybe worth thinking about.=A0=A0 Reading the posts so far, 'JNT= interest could be rekindled, so may yet apply for my NoV - although with= a total house plot of only some 25 x =A07=A0 metres, there not really any= scope for Tx antennas unless I use ground wires looping over the garden= wall into and along=A0the road at the back
=A0
Andy
=A0


=A0
On 14 December 2010 16:27, Chris <c.a= shby435@btinternet.com> wrote:
HiStefan,
Yes, but 600m is VERY long! The wire= even laying on the ground I would expect to radiate quite well at 137 wit= h that length! And how many watts?? ERP??
I am sure 8970 would do well throu= gh the ground at the sort of powers being spoken about. Probably ideal= for submarines, as Roger says!
Vy 73, Chris, G4AYT.
----- Original Message -----
Sent: Tuesday, December 14, 2010= 2:49 PM
Subject: Re: LF: Earth Electrodes<= /div>

Hi Chris,

But how do you explain that i have crossed= 49.6 km with a 600m spaced earth electrode antenna on 8970 Hz? It was rat= her summer time than winther (regarding QRN)! With the same antenna, my 13= 7 kHz signal was seen 20 dB above noise near Paris in DFCW-3!?????

73, Stefan


Am 14.12.2010 15:15, schrieb Chris:=20
Hi Mal,
Yes, that is what I had concluded yea= rs ago. No harm in trying though!
Further to your previous e-mail to LF= , looks to me like beacons are now becoming the norm on 136/7kHz band and= below. I have no problem with that personally, indeed, I think it prefera= ble to a QSO taking forever! I woud like to see full idents though, no mat= ter how slow.
Vy 73,
Chris, G4AYT.




--
g3xbm-qrp.blogspot.com/=
www.g3xbm.co.= uk
www.youtub= e.com/user/g3xbm
<= /a>G3XBM=A0=A0 GQRP 1678=A0=A0=A0 ISWL G11088
--90e6ba6137d0040e89049761f467--