Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mj03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 4BC29380000F3; Wed, 3 Aug 2011 14:48:41 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QogTY-00017I-2k for rs_out_1@blacksheep.org; Wed, 03 Aug 2011 19:47:28 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QogTX-000179-BN for rsgb_lf_group@blacksheep.org; Wed, 03 Aug 2011 19:47:27 +0100 Received: from out1.ip04ir2.opaltelecom.net ([62.24.128.240]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QogTV-0005H9-NR for rsgb_lf_group@blacksheep.org; Wed, 03 Aug 2011 19:47:27 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AnIBAFaXOU5Ok8E3/2dsb2JhbABClAUDg35EjxV4gTsFAQEFCAEBA0kCLAEBAwUCAQMEDQQBAQolFAEEGgYWCAYTCgECAgEBh13BJ4ZCBIcrnDU X-IronPort-AV: E=Sophos;i="4.67,311,1309734000"; d="scan'208,217";a="341672790" Received: from host-78-147-193-55.as13285.net (HELO xphd97xgq27nyf) ([78.147.193.55]) by out1.ip04ir2.opaltelecom.net with SMTP; 03 Aug 2011 19:47:17 +0100 Message-ID: <003001cc520d$c4adaab0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: Date: Wed, 3 Aug 2011 19:47:17 +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: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: Antennas Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01CC5216.263D9530" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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-SCOLL-SCORE: 0:2:387348736:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039400c89a64e3998097da8 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_002D_01CC5216.263D9530 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Chris Signal over noise is different to max sensitivity. ie signal 10 dB noise = 8 dB therefore S/N 2 dB but with a rhombic the same signal would be 30dB = and noise maybe 12 dB therefore S/N would be 18 dB - a big improvement. = As you say you have a strange set of circumstances, it looks like your = Noise is stronger than signal, therefore you would not hear weak signals = with any sort of antenna. mal/g3kev ----- Original Message -----=20 From: Chris=20 To: RSGB LF Group=20 Sent: Wednesday, August 03, 2011 7:08 PM Subject: LF: Antennas Hi Mal and LF, Well, all I can say is that here the signal to noise ratio on RX is = better on my PA0RDT than it is on my long wire (inverted 'L'). I have = always thought this a bit strange, quite often weak signals that cannot = be seen on the wire are perfectly copied on the PA0RDT. This applies = from 136kHz to 3.8MHz. I cannot see what else it can be other than local = noise/QRM level. 80m is another prime example where the noise has = gradually got worse over the years here. Vy 73, Chris, G4AYT, Whitstable, Kent. ------=_NextPart_000_002D_01CC5216.263D9530 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Chris
Signal over noise is different to max = sensitivity. ie=20 signal 10 dB noise 8 dB therefore S/N 2 dB but with a rhombic the same = signal=20 would be 30dB and noise maybe 12 dB therefore S/N would be 18 dB -  = a big=20 improvement.
As you say you have a strange set of = circumstances, it=20 looks like your Noise is stronger than signal, therefore you would not = hear weak=20 signals with any sort of antenna.
mal/g3kev
 
----- Original Message -----
From:=20 Chris
Sent: Wednesday, August 03, = 2011 7:08=20 PM
Subject: LF: Antennas

Hi Mal and LF,
Well, all I can say is that here the = signal to=20 noise ratio on RX is better on my PA0RDT than it is on my long wire = (inverted=20 'L'). I have always thought this a bit strange, quite often weak = signals that=20 cannot be seen on the wire are perfectly copied on the PA0RDT. This = applies=20 from 136kHz to 3.8MHz. I cannot see what else it can be other than = local=20 noise/QRM level. 80m is another prime example where the noise has = gradually=20 got worse over the years here.
Vy 73,
Chris, G4AYT, Whitstable,=20 Kent.
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