Return-Path: Received: from mtain-dj04.r1000.mx.aol.com (mtain-dj04.r1000.mail.aol.com [172.19.187.140]) by air-mf08.mail.aol.com (v129.4) with ESMTP id MAILINMF081-8bf54beeee19234; Sat, 15 May 2010 14:55:21 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dj04.r1000.mx.aol.com (Internet Inbound) with ESMTP id B0FDC38000127; Sat, 15 May 2010 14:55:19 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ODMV2-0004My-LB for rs_out_1@blacksheep.org; Sat, 15 May 2010 19:54:12 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ODMV1-0004Mp-U9 for rsgb_lf_group@blacksheep.org; Sat, 15 May 2010 19:54:11 +0100 Received: from out1.ip02ir2.opaltelecom.net ([62.24.128.238]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1ODMUy-0005DV-S4 for rsgb_lf_group@blacksheep.org; Sat, 15 May 2010 19:54:11 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ak4JAGuK7ksCYhig/2dsb2JhbACOZAOPFwNxuhCFEAQ X-IronPort-AV: E=Sophos;i="4.53,237,1272841200"; d="scan'208,217";a="323172023" Received: from unknown (HELO xphd97xgq27nyf) ([2.98.24.160]) by out1.ip02ir2.opaltelecom.net with SMTP; 15 May 2010 19:53:00 +0100 Message-ID: <003001caf45f$d675b830$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: "rsgb" Date: Sat, 15 May 2010 19:52:58 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,AWL=0.069,HTML_MESSAGE=0.001,RCVD_ILLEGAL_IP=0.234 Subject: LF: 9 antennas Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01CAF468.37D5E020" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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 x-aol-global-disposition: G x-aol-sid: 3039cdbc9d084beeee1777c3 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_002D_01CAF468.37D5E020 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable LF/MF Not much response regarding antenna development on 9 kHz apart from ac= tive probes and small loops. My approach is a proper resonant antenna, verticals, long wires etc= and resonant on the freq of interest, giving more sensitivity and a= sharp response, keeping out qrm from adjacent frequencies. I am referring to RX antennas at this stage. If qrm is as bad as some say around 9 kHz then small loops and active= probes will only amplify the noise as well as signal, whereas a natur= al resonant antenna will eliminate a lot of noise from adjacent freque= ncies and peak the signal at the frequency of interest as stated above= . de mal/g3kev =20 ------=_NextPart_000_002D_01CAF468.37D5E020 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
LF/MF
Not much response regarding antenna= development on=20 9 kHz apart from active probes and small loops.
My approach is a proper resonant ante= nna,=20  verticals, long wires etc and resonant on the freq of interest,= giving=20 more sensitivity and a sharp response, keeping out qrm from adjac= ent=20 frequencies.
I am referring to RX antennas at this= =20 stage.
If qrm is as bad as some say aro= und 9 kHz then=20 small loops and active probes will only amplify the noise as well= as=20 signal, whereas a natural resonant antenna will eliminate a lot= of noise=20 from adjacent frequencies and peak the signal at the frequency of= interest=20 as stated above.
de mal/g3kev
 
 
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