Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl01.r1000.mx.aol.com (Internet Inbound) with ESMTP id E1193380000B7; Thu, 11 Aug 2011 07:41:57 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QrTct-00009n-6M for rs_out_1@blacksheep.org; Thu, 11 Aug 2011 12:40:39 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QrTcs-00009e-Lr for rsgb_lf_group@blacksheep.org; Thu, 11 Aug 2011 12:40:38 +0100 Received: from imr-mb01.mx.aol.com ([64.12.207.164]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QrTcq-0007vA-4W for rsgb_lf_group@blacksheep.org; Thu, 11 Aug 2011 12:40:38 +0100 Received: from mtaout-db04.r1000.mx.aol.com (mtaout-db04.r1000.mx.aol.com [172.29.51.196]) by imr-mb01.mx.aol.com (8.14.1/8.14.1) with ESMTP id p7BBeQm9026390 for ; Thu, 11 Aug 2011 07:40:26 -0400 Received: from [192.168.1.68] (host-92-6-229-92.as43234.net [92.6.229.92]) by mtaout-db04.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 68E3EE00011B for ; Thu, 11 Aug 2011 07:40:25 -0400 (EDT) From: g4gvw To: rsgb_lf_group@blacksheep.org In-Reply-To: References: <4E418609.6020500@iup.uni-heidelberg.de> <67A6F7BF45BF4A0193A3DCB53000A283@PcMinto> <008401cc56ce$2f1fb2c0$0401a8c0@xphd97xgq27nyf> <12C475F3F4C84B818461753F2E8A60A6@PcMinto> <4E41AECB.90808@iup.uni-heidelberg.de> <8D68749D37B94275855FDBA46A3F6C97@PcMinto> <4E427DFB.50801@iup.uni-heidelberg.de> Date: Thu, 11 Aug 2011 12:40:05 +0100 Message-ID: <1313062805.1869.13.camel@pat-compaq-evo> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 X-AOL-SCOLL-SCORE: 0:2:391750848:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: HB9ASB... Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit 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=none 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: 0:2:419836352:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d4acf4e43c0041107 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi All, Roelof rather beat me to a comment. The use of optical "transmission" lines is, these days, an entirely practical solution to many problems. Optical devices are available for operation from baseband to very high frequencies. The technology is out there. What is missing in amateur radio circles seems to be the applications. I remember quite a few years ago when working with Alan G3NYK, he proposed optical coupling at MF in an experimental tx. Unfortunately the client "fell over"(commercially) and we never got the chance to do the work but the application was a very elegant solution to a particular problem at the time. 73 On Thu, 2011-08-11 at 12:26 +0200, Roelof Bakker wrote: > Hello Andy, > > The antenna will work with an optical feedline. > I can't imagine that fiber optic forms the other half of the dipole. > > The probe capacitance is rather low, about 3 pF. > My guess is that the "counterpoise" is formed by the PCB part, carrying > the buffer amplifier. > > The layout of the PCB art work has some effect on the received signal > strength. > Using leaded components, the pick up area measures 30 x 40 mm. > A PCB with SMD parts will give the same output with an "antenna" measuring > 24 x 30 mm. > > 73, > Roelof, pa0rdt > -- 73 es gd dx de pat g4gvw qth nr felixstowe uk (east coast, county of suffolk)