LF: Fwd: News from Harry, G3MFW]

Wed, 14 Jan 1998 19:37:17 -0500

This is a multi-part message in MIME format.
--------------71FF275B1FD05DE54CE8AB5D
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

More interesting details

André

--------------71FF275B1FD05DE54CE8AB5D
Content-Type: message/rfc822
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Return-Path: <owner-rsgb_lf_group@troy.blacksheep.org>
Received: from postoffice2.bellatlantic.net ([199.45.32.41])
          by postoffice3.bellatlantic.net (Post.Office MTA v3.1
          release PO203a  ID# 0-36905U39000L2S100) with ESMTP id AAA16407
          for <akestelo@bellatlantic.net>; Wed, 14 Jan 1998 18:20:20 -0500
Received: from postoffice.bellatlantic.net ([199.45.32.39])
          by postoffice2.bellatlantic.net (Post.Office MTA v3.1
          release PO203a  ID# 0-43173U39000L2S100) with ESMTP id AAA27860
          for <akestelo@bellatlantic.net>; Wed, 14 Jan 1998 18:24:00 -0500
Received: from pmdfsrv.bellatlantic.net ([199.45.32.45])
          by postoffice.bellatlantic.net (Post.Office MTA v3.1
          release PO203a  ID# 0-43172U39000L2S100) with ESMTP id AAA15417
          for <akestelo@bellatlantic.net>; Wed, 14 Jan 1998 18:30:41 -0500
Received: from mail3.bellatlantic.net ([151.199.0.38])
          by pmdfsrv.bellatlantic.net (Post.Office MTA v3.1 release PO203a 
          ID# 0-43174U117000L2S100) with ESMTP id BCS18599
          for <akestelo@bellatlantic.net>; Wed, 14 Jan 1998 18:15:56 -0500
Received: from troy.blacksheep.org (root@troy.blacksheep.org [193.123.212.20])
          by mail3.bellatlantic.net (8.8.5/8.8.5) with SMTP
	  id RAA25650 for <akestelo@bellatlantic.net>; Wed, 14 Jan 1998 17:35:23 -0500 (EST)
Received: (from root@localhost) by troy.blacksheep.org (8.6.12/8.6.12) id XAA08191 for rsgb_lf_group-outgoing; Wed, 14 Jan 1998 23:50:17 GMT
Received: from post.mail.demon.net (post-10.mail.demon.net [194.217.242.154]) by troy.blacksheep.org (8.6.12/8.6.12) with SMTP id XAA08187 for <rsgb_lf_group@blacksheep.org>; Wed, 14 Jan 1998 23:50:14 GMT
Received: from pagnell.demon.co.uk ([158.152.83.229]) by post.mail.demon.net
           id aa1016294; 14 Jan 98 22:15 GMT
Message-ID: <9XyPVBAZ4Rv0EwHb@pagnell.demon.co.uk>
Date: Wed, 14 Jan 1998 20:20:41 +0000
To: rsgb_lf_group@blacksheep.org
From: John W Gould <g3wkl@pagnell.demon.co.uk>
Subject: LF: Fwd: News from Harry, G3MFW
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=iso-8859-1
X-Mailer: Turnpike Version 3.03a <S+lGgVcb4yqdUm+lkNL7W0tgpG>
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org

Dear John,
Happy New Year! I have at last completed my 2 turn loop, delayed first
by a bad back, then impossible weather. The loop is vertical in the E-W
plane and goes right over the house. It is made of 40way telephone cable
with all turns in parallel. R = 0.18 ohms, L =  175 microhenries,
resonating C = 28000pf  polypropylene, Q =  72. It is fed  between the
two turns with my ancient valve amplifier with two KT66s in the PA
running at 500v giving about 56 watts dc input.  Oscillator is crystal
and divider design by Andy, giving 72.1 Khz. (VFO also available).
Keying by my callsign cut in a rotating disc with a hacksaw, via a
transistor and relay which switches the valve amp input between earth
and the divider. Amp input resistance is 1 meg, and divider is loaded
with 300 ohms, so no disturbance of phase of oscillator during keying. I
get 5 amps RF in the loop, measured with thermocouple RF ammeter, and
about  500v across the 2 turns. I also have Andys excellent slow morse
computer program, so can use this if required.

        I received the conventional (very bad!) morse in Truro 20Km to
the west, using a 31 turn shielded loop feeding a Datong VLF converter,
feeding my old Yaesu FR 101 with 600 Khz bandwidth, in turn feeding an
old Datong analogue filter with 100 Hz bandwidth. The only way I could
find the signal amongst the deafening noise was by using my portable
Xtal oscillator, also tuned to 72.1 Khz, as a marker. There were 11KV
overhead wires everywhere. I received nothing at all with a wire
antenna, or the loop not carefully tuned and interference nulled out. I
plan further tests to the east (over the sea), and am building a 400watt
valve amplifier.

        I realise these results are very poor, but they might encourage
other amateurs who are impecunious pensioners like me with no formal
training in electronics. Anyway I have had lots of fun, and would be
delighted to put out test signals on telephone request. I need two
minutes notice for horrible morse, but an hour or so to carry my
computer into the garage for professional slow morse!

Harry, St. Austell, G3MFW phone 01726 73608

12th Jan 98

-- 
John Gould, G3WKL
G3WKL @GB7BEN.#43.GBR.EU
g3wkl@pagnell.demon.co.uk

--------------71FF275B1FD05DE54CE8AB5D--