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=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, 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 u52KbVCC010985 for ; Thu, 2 Jun 2016 22:37:31 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1b8ZFP-0006cV-G0 for rs_out_1@blacksheep.org; Thu, 02 Jun 2016 21:29:43 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1b8ZFO-0006cM-IU for rsgb_lf_group@blacksheep.org; Thu, 02 Jun 2016 21:29:42 +0100 Received: from mail-yw0-x229.google.com ([2607:f8b0:4002:c05::229]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1b8ZFM-0000nj-3H for rsgb_lf_group@blacksheep.org; Thu, 02 Jun 2016 21:29:41 +0100 Received: by mail-yw0-x229.google.com with SMTP id h19so61577739ywc.0 for ; Thu, 02 Jun 2016 13:29:38 -0700 (PDT) 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; bh=3RXVmtrHIo479jC+wc+IXrdMqPSzVMkAEewnsZrTbqg=; b=SUP6W5JzAlaF98brf61qLEQ53+dy3q3bItTmSKPwoRVYvoQgQP1/deNrenf2RtQks8 qQhRrhb/kH52ruJKR8V/Y9ZJzCj0lvQLBGfMaFgy5+WD0cxO5r+03QhLFYAGMKB+MiLe B+BfI5TVvxdfmfMYFnrY8Rp2LomB+P1Ynbi3zfJFPYwVvNY5HejO4q4cpBE0uE2YRWBb 2wSkjhx0vEp4dtMnwJMPzdXg2RdsDIRdc0DCUS+bRPVfJ9E4TldhbGXJ4i0ziB3735di 0erv4BvvRkvK1xEpK3KxjZN+7Yz8bxjI3abTYLooX0B0KzP5xfyr1asJAIkaxEUNSNUy t/OA== 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; bh=3RXVmtrHIo479jC+wc+IXrdMqPSzVMkAEewnsZrTbqg=; b=PoaYt2QRkl5STZd47NrI6mJQAuJshjRdPAPBRq0TUY9FxzTAS8bgSCnee3hCGTDv3C bRZMLUJtWqmQEXDRLlJngigX2SknPZd8d2STwcWgsmDk7tmNmdNCU5TDc2t9dbomBVI8 OFOKw+STQaY2EPwsqEgZLiKWdboH5u7jMsGt1WMBxMTtE+yJ3qwghiCizkPyiB1Lifc8 oukHSUTVNHs6+CQ1JH4XCfcoB46HbI6/dWtVwHNlxbRPlpBU6liLiBf7l3LMQBXAM1IG xgWA9dhHZXqT05YtC+ImQ6PTQu7IBK5NFf0pIWeOvKv619Q12KjVK58alb9mS351komb m7yA== X-Gm-Message-State: ALyK8tLu3Db0kGoBwrzaaqxyJETPl74JPbym5OOPdtVPHLodLMcZ7/euX7Slmf0f8cBrOq0tP6HvV/MGi/hLPw== MIME-Version: 1.0 X-Received: by 10.37.59.150 with SMTP id i144mr69353yba.34.1464899376838; Thu, 02 Jun 2016 13:29:36 -0700 (PDT) Received: by 10.37.75.131 with HTTP; Thu, 2 Jun 2016 13:29:36 -0700 (PDT) In-Reply-To: <1685128417.20160531153441@chriswilson.tv> References: <1685128417.20160531153441@chriswilson.tv> Date: Thu, 2 Jun 2016 21:29:36 +0100 Message-ID: From: Roger Lapthorn To: "rsgb_lf_group@blacksheep.org" X-Scan-Signature: 0cdfd8d5ce44f1724c623c4ac9f44df6 Subject: Re: LF: Earth modes and ebnaut? Content-Type: multipart/alternative; boundary=001a114ecf16fd03220534517602 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: 8210 --001a114ecf16fd03220534517602 Content-Type: text/plain; charset=UTF-8 Chris, Some years ago (before my stroke!) I had correspondence with OFCOM about earth-mode (through the ground conduction) communication at VLF. Basically *they did not want to know* and were not at all bothered unless "undue interference" was caused to other users. As basically pen pushing bureaucrats they had *no interest at all*. To be honest, they found it too hard! My distinct impression is go ahead and do *not* bother with licences! I have used earth-mode at up to about 18kHz, although I'd like to try higher frequencies at some point. In my experience pure earth-mode works best with LOW conductivity between the electrodes, so the signal spreads. Here, I am talking about conduction/induction communication. Stefan DK7FC used radiation I believe, using his earth-electrode "antenna" essentially as a loop radiator. This is my interpretation of how my earth-electrode "antenna" works at 136 and 472kHz. Don't quote me - this is my interpretation of what OFCOM said. It is not a legal statement. 73s Roger G3XBM On 31 May 2016 at 15:34, Chris Wilson wrote: > 31 May 2016 > > > Assuming it's legal to transmit VLF using earth modes, and this seems > an grey area, is anyone using Ebnaut for this communication method? if > I tried to master the complexities of it, not being very > mathematically astute, would anyone be likely to hear or look for a > signal? I am in north Shropshire, in open countryside, with plenty of > space for well separated earth rods, and the means to drive them very > deep into a soild of loam top, about a meter deep, then into what is > normally very wet sand as the water table here is high for most of the > year. Thanks > > > > -- > > > Best regards, > Chris 2E0ILY mailto:chris@chriswilson.tv > > > > --001a114ecf16fd03220534517602 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Chris,

Some years ago (be= fore my stroke!) I had correspondence with OFCOM about earth-mode (through = the ground conduction) communication at VLF. Basically they did not want= to know and were not at all bothered unless "undue interference&q= uot; was caused to other users. As basically pen pushing bureaucrats they h= ad no interest at all. To be honest, they found it too hard!=C2=A0 M= y distinct impression is go ahead and do not bother with licences! I= have used earth-mode at up to about 18kHz, although I'd like to try hi= gher frequencies at some point.

In my experience pure ear= th-mode works best with LOW conductivity between the electrodes, so the sig= nal spreads.

Here, I am talking about conducti= on/induction communication. Stefan DK7FC used radiation I believe, using hi= s earth-electrode "antenna" essentially as a loop radiator. This = is my interpretation of how my earth-electrode "antenna" works at= 136 and 472kHz.

Don't quote me - this is my interpretatio= n of what OFCOM said. It is not a legal statement.

73s
Roger G3XBM

On 31 May 2016 at 15:34, Chris Wilson <chris@chriswilson.tv= > wrote:
31 May 2016


Assuming it's legal to transmit VLF using earth modes, and this seems an grey area, is anyone using Ebnaut for this communication method? if
I tried to master the complexities of it, not being very
mathematically astute, would anyone be likely to hear or look for a
signal? I am in north Shropshire, in open countryside, with plenty of
space for well separated earth rods, and the means to drive them very
deep into a soild of loam top, about a meter deep, then into what is
normally very wet sand as the water table here is high for most of the
year. Thanks



--


Best regards,
=C2=A0Chris=C2=A0 2E0ILY=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0mailto:chris@chriswilson.tv




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