X-GM-THRID: 1208155718140728924 X-Gmail-Labels: rsgb lf X-Gmail-Received: 26017f5ba3152cf81f673dc62cd1c5df71ff881f Delivered-To: daveyxm@gmail.com Received: by 10.64.249.17 with SMTP id w17cs158608qbh; Thu, 6 Jul 2006 04:57:58 -0700 (PDT) Received: by 10.48.143.9 with SMTP id q9mr394707nfd; Thu, 06 Jul 2006 04:57:58 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id n22si8102883nfc.2006.07.06.04.57.57; Thu, 06 Jul 2006 04:57:58 -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 1FySRs-0005kC-9g for rs_out_1@blacksheep.org; Thu, 06 Jul 2006 12:55:12 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1FySRr-0005k3-Pn for rsgb_lf_group@blacksheep.org; Thu, 06 Jul 2006 12:55:11 +0100 Received: from amsfep17-int.chello.nl ([213.46.243.15] helo=amsfep19-int.chello.nl) by relay1.thorcom.net with esmtp (Exim 4.62) (envelope-from ) id 1FySRo-0002wu-OL for rsgb_lf_group@blacksheep.org; Thu, 06 Jul 2006 12:55:11 +0100 Received: from MARLEEN ([80.56.66.191]) by amsfep19-int.chello.nl (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with SMTP id <20060706115117.LNQB24171.amsfep19-int.chello.nl@MARLEEN> for ; Thu, 6 Jul 2006 13:51:17 +0200 Message-ID: <003301c6a0f2$7eeed930$bf423850@MARLEEN> From: "PA0WFO" To: References: Date: Thu, 6 Jul 2006 13:51:19 +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 V6.00.2900.2869 X-Spam-Score: 0.5 (/) X-Spam-Report: autolearn=disabled,AWL=-0.998,DNS_FROM_RFC_POST=1.376,FORGED_RCVD_HELO=0.05,HTML_60_70=0.027,HTML_MESSAGE=0.001 Subject: LF: Re: Loading Coil Q Content-Type: multipart/alternative; boundary="----=_NextPart_000_0030_01C6A103.42649660" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_40_50,HTML_FONTCOLOR_BLUE, 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: 4895 This is a multi-part message in MIME format. ------=_NextPart_000_0030_01C6A103.42649660 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To All , Lacking a "Q"meter I use the following procedure :=20 Connect the coil in series with a variable capacitor to a noise bridge = with the RX output of the bridge to a receiver ( small bandwith of a few = hundred cycles ) on 137 Khz . Bring the the bridge to resonance with = the variable capacitor and the internal potmeter of the bridge and read = the loss resistance of the coil . The Q factor is the Xl of the coil divided by the loss resistance . With = this procedure the "Q"is measured on the working frequency . With a good = shielded Rx and bridge very precise measurements are possible . By = replacing the capacitor with the real life antenna , measurements of = the total resistance to be matched is possible . 73, William PA0WFO ----- Original Message -----=20 From: "Gary - G4WGT" To: "LF (Rsgb LF Group)" Cc: "LW Wave" Sent: Thursday, July 06, 2006 11:38 AM Subject: LF: Loading Coil Q > Hi All, >=20 > Thanks to all for additional comments on the previous thread 'LF = Loading > Coils'. >=20 > Continuing on the theme of loading coils, is there a simple method of > calculating the 'Q' of an LF loading coil without using a 'Q' meter (a > device I have not got access to). I would like to carry out my own > tests/experiments on my antenna system, it can only add to my = knowledge > base. >=20 > 73 >=20 > Gary - G4WGT. >=20 >=20 > ------=_NextPart_000_0030_01C6A103.42649660 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
To=20 All ,
Lacking a = "Q"meter I use=20 the following procedure :
Connect the = coil in=20 series with a variable capacitor to a noise bridge with the RX output of = the=20 bridge to a receiver ( small bandwith of a few hundred cycles )  on = 137=20 Khz . Bring the the bridge to resonance with the variable capacitor = and the=20 internal potmeter of the bridge and read the  loss resistance of = the coil=20 .
The Q = factor is the Xl of=20 the coil divided by the loss resistance . With this procedure the "Q"is = measured=20 on the working frequency . With a good shielded Rx and bridge very = precise=20 measurements are possible . By replacing the capacitor with the real = life=20 antenna ,  measurements of the total resistance to be matched is = possible=20 .
73, William = PA0WFO
 
 
----- = Original Message=20 -----
From: "Gary = - G4WGT"=20 <g4wgt@tiscali.co.uk>
To: "LF = (Rsgb LF Group)"=20 <rsgb_lf_group@blacksheep.org>
Cc: "LW = Wave"=20 <lowfer@lwca.org>
Sent: = Thursday, July 06,=20 2006 11:38 AM
Subject: = LF: Loading Coil=20 Q

> Hi All,
>
> Thanks to all for additional = comments on=20 the previous thread 'LF Loading
> Coils'.
>
> = Continuing on=20 the theme of loading coils, is there a simple method of
> = calculating the=20 'Q' of an LF loading coil without using a 'Q' meter (a
> device I = have not=20 got access to). I would like to carry out my own
> = tests/experiments on my=20 antenna system, it can only add to my knowledge
> base.
> =
>=20 73
>
> Gary - G4WGT.
>
>=20
> ------=_NextPart_000_0030_01C6A103.42649660--