Return-Path: Received: from mtain-dd01.r1000.mx.aol.com (mtain-dd01.r1000.mx.aol.com [172.29.64.141]) by air-me08.mail.aol.com (v129.4) with ESMTP id MAILINME084-8bbf4d07ca5344; Tue, 14 Dec 2010 14:49:39 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4569038000086; Tue, 14 Dec 2010 14:49:35 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PSarX-0003KQ-HH for rs_out_1@blacksheep.org; Tue, 14 Dec 2010 19:48:39 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PSarW-0003KH-U3 for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 19:48:38 +0000 Received: from out1.ip03ir2.opaltelecom.net ([62.24.128.239]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PSarT-0006ZZ-Oe for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 19:48:38 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhYFAHJZB01cEYbG/2dsb2JhbACRXwOGc4s+eMJvhUoEgWCMS4JY X-IronPort-AV: E=Sophos;i="4.59,344,1288569600"; d="scan'208,217";a="329832954" Received: from unknown (HELO xphd97xgq27nyf) ([92.17.134.198]) by out1.ip03ir2.opaltelecom.net with SMTP; 14 Dec 2010 19:48:29 +0000 Message-ID: <009301cb9bc7$de927b10$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <007901cb9bbf$2c223810$0401a8c0@xphd97xgq27nyf> Date: Tue, 14 Dec 2010 19:47:08 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: BODGE ANTENNAS Content-Type: multipart/alternative; boundary="----=_NextPart_000_008C_01CB9BC7.B13C5730" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE 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-sid: 3039ac1d408d4d07ca4e175f X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_008C_01CB9BC7.B13C5730 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Roger=20 What you are using is a vertical grounded LOOP. I have made no attempt= to receive DK7FC because I do not have the time to waste waiting for= a 600 sec dot or longer transmission. I am QRL on all the other amate= ur bands on CW and SSB plus so many other interests beside amateur rad= io. also my soldering iron seldom gets time to cool with the building projects= that are in hand. g3kev =20 =20 ----- Original Message -----=20 From: Roger Lapthorn=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Tuesday, December 14, 2010 7:10 PM Subject: Re: LF: BODGE ANTENNAS Mal, Please, I make no magical claims for the earth electrode antenna I= use. All I say is that, in certain circumstances, it works rather bet= ter than one might expect both on RX and TX on VLF/LF/MF. In my view it does work as a loop antenna on 136 and 500kHz with the= loop area being determined by the soil conductivity (lower conductivi= ty, bigger loop area). The very fact that it is low-Q does suggest lo= ss. Yes, a fully "in the air" loop works better on both 136 and 500kHz= . On 8-9kHz it is far less clear if this is acting as a loop or just= a voltage potential in the ground. Making an efficient "in the air"= TX loop at 8-9kHz may be a challenge. I've managed to receive DK7FC on 8.97kHz - have you? - and this was= using the very same earth electrode system being used for my earth mo= de experiments, and for recent tests on 500kHz. A "proper" loop antenn= a would have yielded several dB improvement in received signal level= on 8.97kHz I do accept. Again, all I am claiming is the structure is worth trying in some si= tuations, not that it works by some sort of magic potion that has been= fermented in my garage.=20 73s Roger G3XBM On 14 December 2010 18:45, mal hamilton wrot= e: I am of the opinion what some on here describe as Earth Mode anten= nas are BODGE antennas. Old timers cannot be fooled but it is very misleading for New come= rs to LF/MF G3KEV --=20 g3xbm-qrp.blogspot.com/ www.g3xbm.co.uk www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 ------=_NextPart_000_008C_01CB9BC7.B13C5730 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Roger
What you are using is a vertical grou= nded LOOP. I=20 have made no attempt to receive DK7FC because I do not have the time= to waste=20 waiting for a 600 sec dot or longer transmission. I am QRL= on all the=20 other amateur bands on CW and SSB plus so many other interests beside= amateur=20 radio.
also
my soldering iron seldom gets time to= cool with the=20 building projects that are in hand.
g3kev
 
 
----- Original Message -----
Sent: Tuesday, December 14,= 2010 7:10=20 PM
Subject: Re: LF: BODGE ANTENN= AS

Mal,

Please, I make no magical claims= for the=20 earth electrode antenna I use. All I say is that, in certain circums= tances, it=20 works rather better than one might expect both on RX and TX on=20 VLF/LF/MF.

In my view it does work as a loop antenna= on 136 and=20 500kHz with the loop area being determined by the soil conductivity= (lower=20 conductivity, bigger loop area).  The very fact that it is low-= Q does=20 suggest loss. Yes, a fully "in the air" loop works better on both 13= 6 and=20 500kHz. On 8-9kHz it is far less clear if this is acting as a loop= or just a=20 voltage potential in the ground. Making an efficient "in the air" TX= loop at=20 8-9kHz may be a challenge.

I've managed to receive DK7FC on= 8.97kHz -=20 have you? - and this was using the very same earth electrode system= being used=20 for my earth mode experiments, and for recent tests on 500kHz. A "pr= oper" loop=20 antenna would have yielded several dB improvement in received signal= level on=20 8.97kHz I do accept.

Again, all I am claiming is the structur= e is worth=20 trying in some situations, not that it works by some sort of magic= potion that=20 has been fermented in my garage.

73s
Roger=20 G3XBM





On 14 December 2010 18:45, mal hamilton <g3ke= vmal@talktalk.net>=20 wrote:
I am of the opinion what some on= here describe=20 as Earth Mode antennas are BODGE antennas.
Old timers cannot be fooled but= it is very=20 misleading for New comers to LF/MF
G3KEV
 



= --
g3xbm-qrp.blogspot.com/
www.g3xbm.co.uk
www.youtube.com/user/g3xbm=
G3XBM&n= bsp;  GQRP 1678    ISWL=20 G11088
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