Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk05.r1000.mx.aol.com (Internet Inbound) with ESMTP id F41FD380000B2; Sat, 31 Mar 2012 10:52:35 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SDzea-0008IW-44 for rs_out_1@blacksheep.org; Sat, 31 Mar 2012 15:51:44 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SDzeZ-0008IM-Jr for rsgb_lf_group@blacksheep.org; Sat, 31 Mar 2012 15:51:43 +0100 Received: from authsmtp05.register.it ([81.88.48.55] helo=authsmtp.register.it) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1SDzeX-0000us-5x for rsgb_lf_group@blacksheep.org; Sat, 31 Mar 2012 15:51:43 +0100 Received: (qmail 12011 invoked from network); 31 Mar 2012 14:51:34 -0000 Received: from unknown (HELO ?1.176.204.109?) (smtp@netlabitalia.it@31.188.128.72) by authsmtp.register.it with ESMTPA; 31 Mar 2012 14:51:34 -0000 References: <09E42DF1-E8AD-4815-A393-0696858718DF@numeo.fr> From: IZ2JGB X-Mailer: iPhone Mail (9B176) In-Reply-To: <09E42DF1-E8AD-4815-A393-0696858718DF@numeo.fr> Message-Id: <8D6D076A-CC45-4505-A132-5341C890D16B@arimi.it> Date: Sat, 31 Mar 2012 16:51:28 +0200 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (1.0) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Transmission characteristics of a two-wire telephone line Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=TO_ADDRESS_EQ_REAL 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-SCORE: 0:2:474904160:93952408 x-aol-sid: 3039ac1db4094f771a32510f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hello. Just use a pair of hdsl Modems And a router and you'll have A data circuit on top of The POTS Line. 73 Giorgio Inviato da iPhone Il giorno 31/mar/2012, alle ore 16:40, John Rabson ha= scritto: > I have received an enquiry from an Italian caver about using such a line t= o transmit speech, text and images of unspecified characteristics from one u= nderground location to another. It is not clear whether the cable will be in= a tunnel or in a cave. >=20 > The total cable length is about 800 metres. For speech communications, hi= s team intends to use field telephones (which are obviously going to work ok= ay), but he would like to be able to transmit other things. I have sent him c= opies of a couple ofCREGJ articles on underground video, but before I can ad= vise him further I need some appreciation of the attenuation versus frequenc= y characteristics of the type of line he wishes to use. >=20 > Can anyone advise, please? >=20 > John F5VLF >=20 >=20 >=20