Return-Path: Received: (qmail 1043 invoked from network); 12 Dec 2002 16:07:13 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 12 Dec 2002 16:07:13 -0000 X-Priority: 3 Received: (qmail 6139 invoked from network); 12 Dec 2002 16:06:45 -0000 X-MSMail-Priority: Normal Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 12 Dec 2002 16:06:45 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18MVpL-00038E-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 12 Dec 2002 16:04:43 +0000 Received: from [213.218.77.54] (helo=cmailENV2.svr.pol.co.uk) by post.thorcom.com with esmtp (Exim 4.10) id 18MVpK-000370-00 for rsgb_lf_group@blacksheep.org; Thu, 12 Dec 2002 16:04:42 +0000 Received: from [62.21.130.71] (helo=w8k3f0.freeler.nl) by cmailENV2.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 18MVpE-0000hV-00 for rsgb_lf_group@blacksheep.org; Thu, 12 Dec 2002 16:04:38 +0000 Message-ID: <5.1.0.14.0.20021212165446.009edbe0@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 12 Dec 2002 17:08:16 +0100 To: rsgb_lf_group@blacksheep.org From: "Dick Rollema" In-reply-to: <4AD4D6A4.09E498F5.28FF0FBC@aol.com> MIME-Version: 1.0 Subject: Re: LF: Antenna tests Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=-1.3 required=5.0tests=BIG_FONT,EMAIL_ATTRIBUTION,IN_REP_TO,SPAM_PHRASE_00_01version=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit To All from PA0SE

Markus wrote:

Though I normaly really dislike the cold weather (as does my 17-year-old Golf Diesel which is supposed to take me to work), the one good thing about frost is the improving LF-antenna performance. Series loss resistance goes down by 1 to 2dB, and surprisingly, in addition to that I seem to get another 1dB from increased effective antenna height, as measured by comparing received voltage against a non-resonant loop. There are a few high fir trees in the vicinity of the aerial, and I assume that under heavy frost, the shunt conductance of the trunks falls below the capacity of the tree crowns, so that electrostatic shielding is significantly reduced.

I measured the earth resistance at my station several times this year:

On the dry day of 6 April it was 21 ohm

On rainy day 5 May I measured 36 ohm

After a period of prolonged rain I found on 16 November 66 ohm

After several days of frost I found today 12 December 28 ohm.

There are no trees around.

The water table here is at about - 0.8m.

73, Dick, PA0SE