Return-Path: Received: from rly-da09.mx.aol.com (rly-da09.mail.aol.com [172.19.129.83]) by air-da07.mail.aol.com (v126.13) with ESMTP id MAILINDA072-a8c4b2cda393a8; Sat, 19 Dec 2009 08:51:00 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da09.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDA094-a8c4b2cda393a8; Sat, 19 Dec 2009 08:50:51 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NLzdD-0001nM-Ls for rs_out_1@blacksheep.org; Sat, 19 Dec 2009 13:46:03 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NLzdD-0001nD-AK for rsgb_lf_group@blacksheep.org; Sat, 19 Dec 2009 13:46:03 +0000 Received: from fmailhost04.isp.att.net ([207.115.11.54]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NLzh8-0004Mz-RL for rsgb_lf_group@blacksheep.org; Sat, 19 Dec 2009 13:50:09 +0000 Received: from [10.0.252.100] (166-82-181-251.stanlynet.org?[166.82.181.251]) by worldnet.att.net (frfwmhc04) with ESMTP id <20091219134959H0400skchie>; Sat, 19 Dec 2009 13:50:00 +0000 X-Originating-IP: [166.82.181.251] Message-ID: <4B2CDA00.6080504@att.net> Date: Sat, 19 Dec 2009 08:49:52 -0500 From: Dexter McIntyre W4DEX User-Agent: Messenger 9.0a1 (Windows/20071115) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <38A51B74B884D74083D7950AD0DD85E828ACB3@File-Server-HST.hst.e-technik.tu-darmstadt.de> <346854e9698cbf94f4483c66682bb63b.squirrel@webmail.xs4all.nl> In-Reply-To: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Noise cancelling by using optic transmission of RX signals Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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=1.6 required=5.0 tests=CELL_PHONE_BOOST 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-IP: 193.82.116.20 X-Mailer: Unknown (No Version) James Moritz wrote: > I think the role of the ground with active whips is often neglected - > the output of the whip preamp is the voltage differential between the > whip element and the circuit ground, so the ground connection is just as > much part of the antenna as the whip element itself is. Clearly, an > electrically quiet ground is needed for the active whip, whether this is > provided by the coax feeder or a separate local ground connection. Years ago I built a simple MPF-102 active whip into a gutted VHF coil enclosure of a NMO mobile antenna. I quickly noticed the antenna performed much better when mounted on a vehicle roof than when mounted on a mast. Even when the whip was elevated up to 10 meters above the vehicle the roof mount received much better. As for the optical link, I attempted to link a remote VLF-3 by IR back to the shack. I never got that to work very well but I feel sure someone that knows what they are doing could perfect it. Dex