Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-de02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4036138000086; Mon, 12 Sep 2011 08:46:35 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1R35tF-0007Wj-Mb for rs_out_1@blacksheep.org; Mon, 12 Sep 2011 13:45:33 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1R35t7-0007Ae-IF for rsgb_lf_group@blacksheep.org; Mon, 12 Sep 2011 13:45:25 +0100 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1R35t4-000207-Qw for rsgb_lf_group@blacksheep.org; Mon, 12 Sep 2011 13:45:23 +0100 Received: by wyh13 with SMTP id 13so4772282wyh.16 for ; Mon, 12 Sep 2011 05:45:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=q6bAzl/W7UUbhXaO+brrUXFAPCIu8mAGXGxdwtVK9wY=; b=On590uuXxhrx23pGqCoZkJLER+XEC8zfnT41QJkKSlZjb5aibrRk3eNyaVRlFPbfib EJvnLVprMvQiFjeG4z+/bAo6Gwrf7zqdNwqV0s+wemD+ja/WqAOfb2+INmfcmzr7n48d XRmFQrD6V2nMqWId8H7IqDwWb2QPdPsw+LVQg= Received: by 10.216.53.4 with SMTP id f4mr82800wec.105.1315831517347; Mon, 12 Sep 2011 05:45:17 -0700 (PDT) Received: from [192.168.1.100] (cpc2-cmbg13-0-0-cust876.5-4.cable.virginmedia.com [213.106.115.109]) by mx.google.com with ESMTPS id ek13sm16043839wbb.23.2011.09.12.05.45.14 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 12 Sep 2011 05:45:15 -0700 (PDT) References: <4E6E0AD4.4838.465714@mike.dennison.ntlworld.com> From: Roger Lapthorn X-Mailer: iPod Mail (8F190) In-Reply-To: <4E6E0AD4.4838.465714@mike.dennison.ntlworld.com> Message-Id: <7C5CCAE9-91E2-428C-8C13-DCB915C2ADF5@gmail.com> Date: Mon, 12 Sep 2011 13:45:27 +0100 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (iPod Mail 8F190) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Ferrite antennas Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=TO_ADDRESS_EQ_REAL 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 x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:463350528:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m289.1 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d40ca4e6dff2b3521 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Mike If the ferrite rod was the drain load what was on the gate? 73s Roger G3XBM Via my iPod Touch 4g 2.4GHz handheld. On 12 Sep 2011, at 13:36, "Mike Dennison" wrote: > I have been following the discussion on ferrite receiving antennas - > due to work pressures I am a few weeks behind in reading the mail. > > The use of this type of antenna for LF amateur radio is not new. I > used it successfully as a portable antenna on the old 73kHz band > several years ago. > > I used the existing winding (LItz) an ordinary long-wave broadcast > radio antenna. The rod was about 150mm long. The coil, tuned with a > large fixed C and a variable C, formed the drain load of a 2N3819, > with the output taken from the source. The selectivity was very high > indeed (essential to reduce the huge commercial signal on the 73kHz > band) and sensitivity was adequate to overcome the noise level of my > very sensitive Datong LF converter. > > The interesting thing was that Peter, G3LDO, tried to replicate this > and had poorer results, perhaps indicating that not all long wave > radios had ferrite that worked at 73kHz. > > Mike, G3XDV > ========== >