Return-Path: Received: from mtain-mc08.r1000.mx.aol.com (mtain-mc08.r1000.mx.aol.com [172.29.96.80]) by air-mc06.mail.aol.com (v129.4) with ESMTP id MAILINMC061-a96f4d07c175196; Tue, 14 Dec 2010 14:11:50 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mc08.r1000.mx.aol.com (Internet Inbound) with ESMTP id DDBA838000177; Tue, 14 Dec 2010 14:11:47 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PSaGe-0002HS-Hp for rs_out_1@blacksheep.org; Tue, 14 Dec 2010 19:10:32 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PSaGe-0002HI-2n for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 19:10:32 +0000 Received: from mail-gx0-f173.google.com ([209.85.161.173]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PSaGb-0006Jr-Og for rsgb_lf_group@blacksheep.org; Tue, 14 Dec 2010 19:10:32 +0000 Received: by gxk24 with SMTP id 24so626819gxk.32 for ; Tue, 14 Dec 2010 11:10:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:content-type; bh=44m0QVOzO6e1DXoD3QUx20tjqnjr7nOq1Ni1r1AQb6c=; b=xdVmylrmPnurofJDHdEj0BL2lqO+xWPQg4cf20QMOMa1UNrnRAk+JAPjSxSNysvM5C xq430N2Pfc1fNa6b58oeJ4iDsNwfZgqrVDZwEVxtkg6mjD/H13Ad+xHjfhaSYAOC6rqk jROWLfzT7RlSyvKK7cK01rPT9zrU60MxDLflo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=xzWw/04xi1e9npCTL/9i7xEEyILmniQakL+Nlaqt0lrbSHbMh3k0VwFcNAAScWUFwz i3/LZ8HVVU7/ysBpJ+cmhMSHQonHzW7YGAAWrCuf52ydE8IzrDPv29ukBWpLulSWPKXD lOYRZG9Zs1URa7IFlbL4KVYzqzkYF9AQ4QoFM= MIME-Version: 1.0 Received: by 10.42.172.135 with SMTP id n7mr4797406icz.117.1292353822488; Tue, 14 Dec 2010 11:10:22 -0800 (PST) Received: by 10.42.239.71 with HTTP; Tue, 14 Dec 2010 11:10:22 -0800 (PST) In-Reply-To: <007901cb9bbf$2c223810$0401a8c0@xphd97xgq27nyf> References: <007901cb9bbf$2c223810$0401a8c0@xphd97xgq27nyf> Date: Tue, 14 Dec 2010 19:10:22 +0000 Message-ID: From: Roger Lapthorn To: rsgb_lf_group@blacksheep.org DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: BODGE ANTENNAS Content-Type: multipart/alternative; boundary=90e6ba6137d08378a004976392d6 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-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d281.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d60504d07c1717cf4 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : temperror X-Mailer: Unknown (No Version) --90e6ba6137d08378a004976392d6 Content-Type: text/plain; charset=ISO-8859-1 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 better 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 conductivity, bigger loop area). The very fact that it is low-Q does suggest loss. 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 mode experiments, and for recent tests on 500kHz. A "proper" loop antenna 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 situations, not that it works by some sort of magic potion that has been fermented in my garage. 73s Roger G3XBM On 14 December 2010 18:45, mal hamilton wrote: > I am of the opinion what some on here describe as Earth Mode antennas are > BODGE antennas. > Old timers cannot be fooled but it is very misleading for New comers to > LF/MF > G3KEV > > -- g3xbm-qrp.blogspot.com/ www.g3xbm.co.uk www.youtube.com/user/g3xbm G3XBM GQRP 1678 ISWL G11088 --90e6ba6137d08378a004976392d6 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Mal,

Please, I make no magical claims for the earth electrod= e antenna I use. All I say is that, in certain circumstances, it works rat= her better 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 conductivity,= bigger loop area).=A0 The very fact that it is low-Q does suggest loss.= Yes, a fully "in the air" loop works better on both 136 and 500= kHz. 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&quo= t; TX loop at 8-9kHz may be a challenge.

I've managed to receive DK7FC on 8.97kHz - have you? - and this wa= s using the very same earth electrode system being used for my earth mode= experiments, and for recent tests on 500kHz. A "proper" loop an= tenna 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 situ= ations, not that it works by some sort of magic potion that has been ferme= nted in my garage.

73s
Roger G3XBM





On 14 December 2010 18:45, mal hamilton <g3kevmal@talktalk.net> wrote:
I am of the opinion what some on here= describe as=20 Earth Mode antennas are BODGE antennas.
Old timers cannot be fooled but it is= very=20 misleading for New comers to LF/MF
G3KEV
=A0



--
g3xbm-qrp.blogspot.com/
www.g3xbm.co.uk
= www.youtub= e.com/user/g3xbm
G3XBM=A0=A0 GQRP 1678= =A0=A0=A0 ISWL G11088
--90e6ba6137d08378a004976392d6--