Return-Path: Received: (qmail 20175 invoked from network); 28 Feb 2003 13:32:12 -0000 Received: from netmail01.services.quay.plus.net (212.159.14.219) by mailstore with SMTP; 28 Feb 2003 13:32:12 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 399 invoked by uid 10001); 28 Feb 2003 13:31:57 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com (193.82.116.70) by netmail01.services.quay.plus.net with SMTP; 28 Feb 2003 13:31:57 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18okbZ-0003Bq-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 28 Feb 2003 13:31:13 +0000 Received: from [213.218.77.55] (helo=cmailENV3.svr.pol.co.uk) by post.thorcom.com with esmtp (Exim 4.12) id 18okbU-0003Bh-00 for rsgb_lf_group@blacksheep.org; Fri, 28 Feb 2003 13:31:08 +0000 Received: from [62.21.148.78] (helo=w8k3f0.freeler.nl) by cmailENV3.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 18okbS-0002cr-00 for rsgb_lf_group@blacksheep.org; Fri, 28 Feb 2003 13:31:06 +0000 Message-ID: <5.1.0.14.0.20030228142827.023d8ba0@POP3.freeler.nl> X-Sender: FRE0000086604@POP3.freeler.nl X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Fri, 28 Feb 2003 14:29:53 +0100 To: rsgb_lf_group@blacksheep.org From: "Dick Rollema" In-reply-to: <001c01c2dec6$044de5a0$6507a8c0@Main> MIME-Version: 1.0 Subject: Re: LF: O/C chasing at LF Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=-8.5 required=5.0tests=EMAIL_ATTRIBUTION,HTML_00_10,HTML_MESSAGE,IN_REP_TOversion=2.50 X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Content-transfer-encoding: 8bit Well done, Alan!

This is what I like: clever use of equipment that happens to be available.

73, Dick, PA0SE


At 01:07 28-2-03 +0000, you wrote:
Hi all, I thought this little episode might prove interesting and it
certainly finds a use for the "below 50MHz" part of a hand-held scanner. I
have an AOR 2700 which purports to operate down to 100kHz, but like a lot of
this kind of kit is very deaf down there. I did think it might be useful for
DFing TV interfence, but it is too deaf even for that, without a pre-amp.

I restrung my 60m-top Marconi last weekend and was disappointed to see that
the tunning when paralleled with my 30m top inv-L was not at the original
position. As it is a receive aerial is is strung with 1mm PVC coated wire. A
quick measurement of the tuning inductor indicated only 80pF more capacity,
which I guessed would mean a break inside the insulation about 16m from the
feed point (5pF / m). After a little thought and a couple of coffees, I
plugged the end of the unloaded 60m wire into the 600ohm output of the PS-12
(W&G SIG GEN) turned up full and with the interenal resistor set to "0". I
then walked down the wire (now dropped to the ground again), running the
wire at right-angles over the closed telescopic aerial on the AOR2700. The
"S-meter" gave fullscale on AM, and about 15m down the wire it dropped
significantly ( to "S3"). A quick waggle of the wire confirmed two breaks at
that point. I was quite pleasantly surprised that point indicated by the
scanner s-meter was with an inch of the break. After a quick soldering job
and a tape-up the aerial tuning inductor was back to where it was expected
to be.

I know its not rocket science but its nice when these little tricks really
work. The feed voltage from the PS-12 was about 0.7V r.m.s. It also proved
my contention that a wide coverage receiver is one of the most useful bits
of test gear you can have (I might add "portable" to that as well now!!)

Cheers de Alan G3NYK
alan.melia@btinternet.com