X-GM-THRID: 1243746088775196646 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.70.87.11 with SMTP id k11cs251519wxb; Fri, 3 Aug 2007 11:22:53 -0700 (PDT) Received: by 10.82.108.9 with SMTP id g9mr4196523buc.1186165372868; Fri, 03 Aug 2007 11:22:52 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id f6si9319612nfh.2007.08.03.11.22.49; Fri, 03 Aug 2007 11:22:52 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1IH1iI-0000vA-6L for rs_out_1@blacksheep.org; Fri, 03 Aug 2007 19:17:26 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1IH1iH-0000v1-Jj for rsgb_lf_group@blacksheep.org; Fri, 03 Aug 2007 19:17:25 +0100 Received: from anchor-post-33.mail.demon.net ([194.217.242.91]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1IH1iG-0000rg-CP for rsgb_lf_group@blacksheep.org; Fri, 03 Aug 2007 19:17:25 +0100 Received: from dyn-62-56-85-216.dslaccess.co.uk ([62.56.85.216] helo=Tom) by anchor-post-33.mail.demon.net with esmtpa (AUTH telemetry) (Exim 4.42) id 1IH1iF-0000aH-B0 for rsgb_lf_group@blacksheep.org; Fri, 03 Aug 2007 18:17:23 +0000 Message-ID: <005301c7d5fa$95d20da0$d855383e@Tom> From: "Tom Boucher" To: References: <005001c7d3fe$e4786d80$6400a8c0@oem17oeylz9on8> <001901c7d42b$e6fbeaa0$86048351@w4o8m9> <00a001c7d43c$f4180690$0a7ee150@o> <1IGMYh-02648G0@fwd31.t-online.de> <003001c7d4d1$fcaf0390$db3a383e@Tom> <000101c7d5a4$5f527220$4e69e150@o> <008901c7d5b0$eea7c040$a17d383e@Tom> <000101c7d5e1$f47ba410$d5d3e150@o> Date: Fri, 3 Aug 2007 19:17:42 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Spam-Score: -0.3 (/) X-Spam-Report: autolearn=disabled,AWL=-0.347,HTML_MESSAGE=0.001 Subject: LF: 500 / OLB test-sig... Content-Type: multipart/alternative; boundary="----=_NextPart_000_0050_01C7D602.F6CBD2A0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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 Status: O X-Status: X-Keywords: X-UID: 402 This is a multi-part message in MIME format. ------=_NextPart_000_0050_01C7D602.F6CBD2A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thank you Rog and Brian 'YKB. Rog, tell me where you find the programme you use, 'RFSim'? Brian, thanks for the pointer to the G4FGQ site which looks very useful. = I think G4FGQ is SK now but nice to know his web site is still = available. Also thanks to Dave G3WCB for another report. Tom, G3OLB ----- Original Message -----=20 From: GW3UEP=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Friday, August 03, 2007 4:15 PM Subject: LF: Re: Re: 500 / OLB test-sig... Tom, I use the L-match on all ants, from half-waves to verticals, with a = simple differential version for open-wire doublets. Currently, I have ~3000pF across the 50R coax at the remote feed on MF = [the resonating vario/L forms part of the L-match]. Your 6600pF is a good indication of a low input-resistance and = resistive transformation from 50R downwards towards the ant. Coincidentally, Mike has just tried the L-match with my sensitive = resistive-reflectometer cct - he nulled at 5600pF. Your R_in looks like ~24R [Mike's ~28R]; mine is an appalling ~40R. Rog. P.S. I use the L-match to arrive at i/p resistance by measuring the C/L = values of the nulled cct. Then, use RFSim to simulate the ant load & find X & R_in. The results = can be verified by substitution on the bench. A really good/low R_in [<10R] will require ~15000pF or more on MF. ------=_NextPart_000_0050_01C7D602.F6CBD2A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thank you Rog and Brian = 'YKB.
 
Rog, tell me where you find the = programme you use,=20 'RFSim'?
Brian, thanks for the pointer to the = G4FGQ site=20 which looks very useful. I think G4FGQ is SK now but nice to know his = web site=20 is still available.
 
Also thanks to Dave G3WCB for another=20 report.
 
Tom, G3OLB
----- Original Message -----
From:=20 GW3UEP
Sent: Friday, August 03, 2007 = 4:15=20 PM
Subject: LF: Re: Re: 500 / OLB=20 test-sig...

Tom,
I use the L-match on all ants, from = half-waves=20 to verticals, with a simple differential version for open-wire=20 doublets.
Currently, I have ~3000pF across the = 50R coax at=20 the remote feed on MF [the resonating vario/L forms part of the=20 L-match].
Your 6600pF is a good indication of = a low=20 input-resistance and resistive transformation from 50R downwards = towards the=20 ant.
Coincidentally, Mike has = just tried the=20 L-match with my sensitive resistive-reflectometer cct - he nulled at=20 5600pF.
Your R_in looks like ~24R [Mike's = ~28R]; mine=20 is an appalling ~40R.
Rog.
 
P.S.
I use the L-match to arrive at =  i/p=20 resistance by measuring the C/L values of the nulled cct.
Then, use RFSim to simulate the ant = load &=20 find X & R_in.  The results can be verified by substitution = on the=20 bench.
A really good/low R_in [<10R] = will require=20 ~15000pF or more on MF.
 
 
 
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