Return-Path: Received: (qmail 23095 invoked from network); 9 Apr 2001 07:56:55 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by 10.226.25.101 with SMTP; 9 Apr 2001 07:56:55 -0000 Received: (qmail 6421 invoked from network); 9 Apr 2001 07:56:47 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 9 Apr 2001 07:56:47 -0000 Content-Transfer-Encoding: 8bit Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 14mWRW-0006c4-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 09 Apr 2001 08:50:34 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from bob.dera.gov.uk ([192.5.29.90]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 14mWRV-0006bz-00 for rsgb_lf_group@blacksheep.org; Mon, 09 Apr 2001 08:50:33 +0100 Received: by bob.dera.gov.uk; (8.8.8/1.3/10May95) id IAA27278; Mon, 9 Apr 2001 08:53:22 +0100 (BST) Received: (qmail 24848 invoked from network); 9 Apr 2001 08:40:37 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from gauntlet.mail.dera.gov.uk (172.16.9.10) by baton.dera.gov.uk with SMTP; 9 Apr 2001 08:40:37 -0000 Received: by gauntlet.mail.dera.gov.uk; id IAA29068; Mon, 9 Apr 2001 08:25:48 GMT Received: from unknown(10.71.64.31) by gauntlet.mail.dera.gov.uk via smap (3.2) id xma029026; Mon, 9 Apr 01 08:25:20 GMT Received: from FRN-MAIL-3.dera.gov.uk (unverified) by mailguard.dera.gov.uk (Content Technologies SMTPRS 4.1.5) with ESMTP id for ; Mon, 9 Apr 2001 08:56:02 +0100 Received: by frn-mail-3.dera.gov.uk with Internet Mail Service (5.5.2650.21) id <2MRA5M5D>; Mon, 9 Apr 2001 08:49:31 +0100 Message-ID: <65AECDF1F89AD411900400508BFC869F9C043F@pdw-mail-1.dera.gov.uk> From: "Talbot Andrew" To: rsgb_lf_group@blacksheep.org Subject: LF: RE: Helical antennas Date: Mon, 9 Apr 2001 08:49:43 +0100 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2650.21) Content-Type: text/plain; charset=iso-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: The normal mode helix was covered in some detail in a 1974 (!!) edition of Radio Communication with a set of empirically determined equations for calculating resonance and winding dimensions. Seem to remember it was by the famous D A Tong, but I may be mixing it up with another article. I found the equations to be a good starting point from which to fine tune helials for HF. Used to have a copy of that RadCom, and it may still be lying on a shelf somewhere. Andy G4JNT > -----Original Message----- > From: g3ldo [mailto:g3ldo@ukonline.co.uk] > Sent: 2001-04-06 21:06 > To: rsgb_lf_group@blacksheep.org > Subject: LF: Helical antennas > > > Does anyone have a description of how the helical antenna > (not the axial > mode antenna), like the one built by Toni HB9ASB, works? > > Tony made a lot of tests and concluded that most of the > radiation came from > the helical coil rather than the top loading, see page 58 of the LF > handbook. > > Regards, > Peter, G3LDO > > e-mail > > Web > > > -- The Information contained in this E-Mail and any subsequent correspondence is private and is intended solely for the intended recipient(s). For those other than the recipient any disclosure, copying, distribution, or any action taken or omitted to be taken in reliance on such information is prohibited and may be unlawful.