Return-Path: Received: from rly-da07.mx.aol.com (rly-da07.mail.aol.com [172.19.129.81]) by air-da06.mail.aol.com (v123.3) with ESMTP id MAILINDA063-a7d49a8902c1dd; Fri, 27 Feb 2009 20:15:44 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da07.mx.aol.com (v123.3) with ESMTP id MAILRELAYINDA075-a7d49a8902c1dd; Fri, 27 Feb 2009 20:15:38 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LdDjW-0002tZ-C9 for rs_out_1@blacksheep.org; Sat, 28 Feb 2009 01:11:14 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LdDjV-0002tQ-HS for rsgb_lf_group@blacksheep.org; Sat, 28 Feb 2009 01:11:13 +0000 Received: from vms173001pub.verizon.net ([206.46.173.1]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LdDjN-0005Qa-KR for rsgb_lf_group@blacksheep.org; Sat, 28 Feb 2009 01:11:13 +0000 Received: from DR2 ([71.184.212.10]) by vms173001.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KFR007WC4LFUM2R@vms173001.mailsrvcs.net> for rsgb_lf_group@blacksheep.org; Fri, 27 Feb 2009 19:10:27 -0600 (CST) Message-id: <54FE5A0020614CE8B5E3718965EB957F@DR2> From: "dave.riley3" To: References: <4A11BD1B67394BDD9B3001D8F176B76F@DR2> <001001c99931$cd41ab50$8d01a8c0@JAYDELL> Date: Fri, 27 Feb 2009 20:10:27 -0500 MIME-version: 1.0 X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Karma: unknown: X-Spam-Score: 3.4 (+++) X-Spam-Report: autolearn=disabled,FORGED_MUA_OUTLOOK=3.36 Subject: LF: Re: Re: Re: LF Antennas - back to basics Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=response 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=FORGED_MUA_OUTLOOK 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 > Dave > > If you believe this I have a bridge you might be interested in > purchasing... > > Jay W1VD WD2XNS WE2XGR/2 No thanks, I have enuf worms for fishing... Besides, I'm lazy and one run of wire outperforms my messy attempts @ loading the trees with HV wires that detune with humidity... We installed a short flat top on the Sea Venture ( WJMV ) and I could tell you what the relative humidity was by the antenna current... Some dielectric measuring device, eh?? 10A into the ground radial common point is power wasted that could have been released into the air... I'm talking about my crummy ground conductivity here ( silica sand ), not on a ship or @ a salt water location... I think!! What bridge?? An RF one?? Dave ----- Original Message ----- From: To: Sent: Friday, February 27, 2009 6:19 PM Subject: LF: Re: Re: LF Antennas - back to basics >> No wasted power going into and out of the ground... > > Dave > > If you believe this I have a bridge you might be interested in > purchasing... > > Jay W1VD WD2XNS WE2XGR/2 > > ----- Original Message ----- > From: "dave.riley3" > To: ; > Sent: Thursday, February 26, 2009 11:53 AM > Subject: LF: Re: LF Antennas - back to basics > > >> Glad you asked, Andy... Hope this one makes it past the spam filter... >> >> Back in the commercial AM transmitter biz days I buried miles of extra >> copper in to poor conductivity soil and gained little or nothing. >> Then came Bill Ashloop who proved that a small transmit loop can do quite >> well. >> http://www.wireless.org.uk/loopy.htm >> http://www.w1tag.com/XESANT.htm >> >> So I surveryed the back yard which sits on very poor conductivity soil >> and therefore makes a loop appear to me more in free space and here are >> the advantages that I have found to date: >> >> No high voltage wire ends to start tree fires. No wasted power going into >> and out of the ground... >> >> Much less wire used in a LOOP transmit antenna. This #4 stranded HV wire >> rests inside of 100' sections of garden hose and is hoisted into trees >> with help of compound bow and pull line. >> >> No top loading, no radials, much less noise on RX, E-Z to tune and >> weather does not affect the tuning much such as from rain or snow, and it >> acts like a good vertical regardless of being much simpler. >> >> As for the CONS, well I just don't think of any... Somebody?? >> >> It works very well from 600M to 6M and is the only real antenna that I >> still have. >> >> Various feeds as noted below will let you tune it down to SAQ@17kc which >> I always hear and also makes for superb DX on 6M in 'some directions'. >> >> ref: http://www.radiocom.net/600M/LOOP109.jpg >> >> Wish I had a El-Nec printout but can't seem to fit this version in to it. >> >> QSL SURE VIA E-MAIL >> 090226 0406 1 -29 0.0 0.503869 G4JNT IO90 23 >> 090226 0610 3 -29 0.0 0.503869 G4JNT IO90 23 >> >> Have a quiet night and TNX from Dave @ WD2XSH/17 >> >> >> >> >> >> >> >> >> ----- Original Message ----- >> From: "Andy Talbot" >> To: >> Sent: Thursday, February 26, 2009 11:16 AM >> Subject: LF: LF Antennas - back to basics >> >> >>> Having now been encouraged by being decoded now by at least two US >>> stations, was wondering how much improvement in efficiency I could >>> scrape out of my existing antenna. It is a Marconi Tee, the vertical >>> element consisting of three wires from the base tapering to 200mm >>> spacing at the top. There it is attached to the centre of a a >>> capacity hat 15m long and 200mm wide made of three parallel wires. >>> >>> The ground system is a bit haphazard in my 7m wide by 12m long garden, >>> with about 4 wires meeting at the base of the antenna meandering >>> around the garden, starting off in different directions from teh base. >>> They are all connected to substantial ground rods in heavy clay at >>> their far points, a with a few randomly spaced rods in between (I used >>> several 1m lengths of 15mm water pipe as well as proper rods - there >>> is probably about 9 or 10 rods in total, mostly 1 - 2m in length - >>> can't remember that far back! Some of the earth conductors were also >>> bonded to the house wiring by a couple of substantial straps, and even >>> inside the house I added more straps at strategic places. I also >>> ensured there was a good fat cable run directly under as much of the >>> capacity hat as possible. As a test, disconnecting the PME earthing >>> bond and measuring the DC resistance between my total set of >>> connections and the incoming conductor ground/neutral point, the value >>> was a pretty consistent 3 ohms. Haven't done this test for a few >>> years, but at the last check it was still of this order. >>> >>> Back in the 73kHz days a number of (mostly big!) stations were >>> surprised my signal was as strong as it was for probably the smallest >>> antenna in use then; G3LDO put it down to the fact I had concentrated >>> plenty of earthing wire to run directly under the top-hat. >>> >>> But, its all 14 years old, still OK, but hopefully there's a wealth >>> of experience now, and I wonder if there are obvious improvements that >>> could be made: >>> >>> Firstly, bearing in mind there is no scope whatsoever to raise one end >>> of the capacity hat which is defined by the apex of the house roof, >>> and the other end would also need some major sugery to raise its heigh >>> substantially, that only leaves the middle, ie the height of the >>> actual radiator. It wouldn't be too difficult to raise this to 10m >>> or even more with a fibreglass pole, but will I be throwing away all >>> the advantage by having the top-hat drooping down to 7m? >>> >>> Secondly, pictures of other peoples antennas aften show a substantial >>> grounding plate immediately under and around the antenna base. Just >>> how far out is is worth going with a really substantial base. I >>> could cut more conductors into the ground; while the ground is still >>> is still soggy in March may be a good time to do this. >>> >>> Any ideas please ...? >>> >>> >>> Andy G4JNT >>> www.g4jnt.com >>> >> >