X-GM-THRID: 1214434992783322238 X-Gmail-Labels: rsgb lf X-Gmail-Received: 66e6bf638f9a4677c0a0efe6edafd9b5dcfbeab1 Delivered-To: daveyxm@gmail.com Received: by 10.64.250.20 with SMTP id x20cs895705qbh; Wed, 13 Sep 2006 12:24:21 -0700 (PDT) Received: by 10.49.10.3 with SMTP id n3mr11261781nfi; Wed, 13 Sep 2006 12:24:21 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id a23si17759731nfc.2006.09.13.12.24.20; Wed, 13 Sep 2006 12:24:21 -0700 (PDT) Received-SPF: neutral (gmail.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 1GNaHa-0006y1-Dz for rs_out_1@blacksheep.org; Wed, 13 Sep 2006 20:20:26 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1GNaHZ-0006xs-PW for rsgb_lf_group@blacksheep.org; Wed, 13 Sep 2006 20:20:25 +0100 Received: from amsfep17-int.chello.nl ([213.46.243.15] helo=amsfep18-int.chello.nl) by relay2.thorcom.net with esmtp (Exim 4.51) id 1GNaHV-00016z-NU for rsgb_lf_group@blacksheep.org; Wed, 13 Sep 2006 20:20:25 +0100 Received: from MARLEEN ([80.56.66.93]) by amsfep18-int.chello.nl (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with SMTP id <20060913192013.DKYN13670.amsfep18-int.chello.nl@MARLEEN> for ; Wed, 13 Sep 2006 21:20:13 +0200 Message-ID: <000801c6d769$a3a3b270$5d423850@MARLEEN> From: "PA0WFO" To: References: <000801c6d757$0c6af2e0$60be3b3e@fujitsu> Date: Wed, 13 Sep 2006 21:20:13 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Spam-Score: -0.6 (/) X-Spam-Report: autolearn=disabled,AWL=-0.660,FORGED_RCVD_HELO=0.05,HTML_60_70=0.027,HTML_MESSAGE=0.001 Subject: LF: Re: antenna calculation..help needed Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C6D77A.66F34A00" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=HTML_40_50,HTML_FONTCOLOR_BLUE, HTML_MESSAGE,MAILTO_TO_SPAM_ADDR 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: 4572 This is a multi-part message in MIME format. ------=_NextPart_000_0005_01C6D77A.66F34A00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Dick , To match a resistive load of 36 Ohms to 50 Ohms you need a L network = consisting of a coil of 0,4 microH from your TX to the antenna and a = capacitor of 195 pF from the 50 Ohms side to ground ( freq, 10,140 Mhz ) = as calculated with the L matching network calculator ( supplied with the = ARRL antennabook ) . I use this calculator quite often with good results = . I will send you the program ( Old MS DOS ) in a seperate E-mail . 73, William PA0WFO ----- Original Message -----=20 From: Dick=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, September 13, 2006 7:06 PM Subject: LF: antenna calculation..help needed Hello all, It's off topic, but as I can't find it on the net I'll ask it here. I want to modify an old 27MHz CB antenna to an quarter wave vertical = for 30m (10.14MHz) Diameter is tapering from 26 to 15mm. Question: what length should it have? I suppose 0.25 wavelength x 0.96 = or so... Sofar not a big problem, but as I will use 36 radials direct on the = ground, it's radiation resitance will be around 36Ohm. To match this to 50Ohm I can use a series capacitor, but what value = this should be?? Who can tell me? 73 Dick, pa4vhf ------=_NextPart_000_0005_01C6D77A.66F34A00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello Dick=20 ,
To match a = resistive load=20 of 36 Ohms to 50 Ohms you need a L network consisting of  a coil of = 0,4=20 microH from your TX to the antenna and a capacitor of 195 pF from the 50 = Ohms=20 side to ground ( freq, 10,140 Mhz ) as calculated with the L matching = network=20 calculator ( supplied with the ARRL antennabook ) . I use this = calculator=20 quite often with good results . I will send you the program ( Old MS DOS = ) in a=20 seperate E-mail .
73, William = PA0WFO
----- Original Message -----
From:=20 Dick
Sent: Wednesday, September 13, = 2006 7:06=20 PM
Subject: LF: antenna = calculation..help=20 needed

Hello all,
 
It's off topic, but as I can't find = it on the net=20 I'll ask it here.
 
I want to modify an old 27MHz CB = antenna to an=20 quarter wave vertical for 30m (10.14MHz)
 
Diameter is tapering from 26 to=20 15mm.
 
Question: what length should it have? = I suppose=20 0.25 wavelength x 0.96 or so...
 
Sofar not a big problem, but as I = will use 36=20 radials direct on the ground, it's radiation resitance will = be
around 36Ohm.
 
To match this to 50Ohm I can use = a series=20 capacitor, but what value this should be??
 
Who can tell me?
 
73
 
Dick,=20 pa4vhf
------=_NextPart_000_0005_01C6D77A.66F34A00--