Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-de05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 48EEE38000210; Sun, 13 May 2012 15:04:03 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1STe4T-0001QS-7x for rs_out_1@blacksheep.org; Sun, 13 May 2012 20:03:09 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1STe4S-0001QJ-K1 for rsgb_lf_group@blacksheep.org; Sun, 13 May 2012 20:03:08 +0100 Received: from out1.ip08ir2.opaltelecom.net ([62.24.128.244]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1STe4P-0008H8-GU for rsgb_lf_group@blacksheep.org; Sun, 13 May 2012 20:03:07 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AucPAJMEsE9cF/vZ/2dsb2JhbABFii+XFZB7AQKBHIEIghAFAQEDAggBAQMlASMCLAEBAwUCAQMRBAEBAQklFAEECBIGDAoIBhMKAQICAQEBh24DDwerYYNiAwoGiU2KLG4cRnGENQSIMIVKiRSKLAOFAIJp X-IronPort-AV: E=Sophos;i="4.75,581,1330905600"; d="scan'208";a="527807655" Received: from host-92-23-251-217.as13285.net (HELO xphd97xgq27nyf) ([92.23.251.217]) by out1.ip08ir2.opaltelecom.net with SMTP; 13 May 2012 20:03:04 +0100 Message-ID: <006001cd313b$03f93e70$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <4FAFEA71.8030700@iup.uni-heidelberg.de><816458997.166418.1336930894168.JavaMail.www@wwinf8305> Date: Sun, 13 May 2012 19:02:59 -0000 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: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Warren Things have gone downhill since the introduction of Ferrite Stick antennas, uProbe antennas etc the K9AY antenna is a good sized loop antenna and does well. I use a 40 metre quad loop for general RX reception and resonate it on the band of interest and it works well but not as good as a full size antenna for MF/LF. If space is available a full size antenna for the band of interest is preferable and if not then the inv L and loop antennas as large as possible are the next best choice, after that pocket size antennas work after a fashion but do not expect miracles. The pocket sized antennas are ok for High power Broadcast reception but poor for weak radio amateur signals. 73 de mal/g3kev [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [62.24.128.244 listed in list.dnswl.org] 0.0 FSL_XM_419 Old OE version in X-Mailer only seen in 419 spam -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FSL_UA FSL_UA X-Scan-Signature: 2ee80849a5d572dbc974bb207a527753 Subject: Re: LF: Cardioid RX antenna for LF... Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.6 required=5.0 tests=CELL_PHONE_BOOST 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: 0:2:486663680:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40cd4fb005a34420 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Warren Things have gone downhill since the introduction of Ferrite Stick antennas, uProbe antennas etc the K9AY antenna is a good sized loop antenna and does well. I use a 40 metre quad loop for general RX reception and resonate it on the band of interest and it works well but not as good as a full size antenna for MF/LF. If space is available a full size antenna for the band of interest is preferable and if not then the inv L and loop antennas as large as possible are the next best choice, after that pocket size antennas work after a fashion but do not expect miracles. The pocket sized antennas are ok for High power Broadcast reception but poor for weak radio amateur signals. 73 de mal/g3kev ----- Original Message ----- From: "Warren Ziegler" To: Sent: Sunday, May 13, 2012 6:34 PM Subject: Re: LF: Cardioid RX antenna for LF... Stefan, See Dallas Lankford's site: http://groups.yahoo.com/group/thedallasfiles/ Yes F1AFJ used a K9AY with excellent results (until a local source of QRM appeared) Jean-Pierre even copied some T/A signals into daylight! Also Jay W1VD and Hartmut Wolff used similar antennas, see: http://w1vd.com/k9ay11.pdf http://jpmere.online.fr/L_F/Les%20LF.htm (scroll to bottom) 73 K2ORS On Sun, May 13, 2012 at 1:41 PM, manginbenoit.pro wrote: > GE Stefan and all, > > Try and see Jean-Pierre / F1AFJ 's page, he built and modeled a 2-turn K9AY, > the one he uses for his grabber. > > Nothing to say about performance, it seems. Judge it by the summer T/A > captures... Plus, (I did not test it) his QSD RX es MMIC preamp seems to > work VY FB. > > I tried a 2-turn K9AY for 160, but it is definetely too long, there is too > much wire. 0,2 lambdas seems to be a maximum. Voltage levels are correct but > directionnal properties degrade seriously. > > Nevermind on 137, we will never reach a quarter-wave long RX antenna !!! > > Maybe a 2-turn Flag should be tested ? Does anybody use MMANA ? I can try > and model one using this software. > > I don't use EZNEC at all. > > de F8GRY/Ben > > > > >> Message du 13/05/12 19:12 >> De : "Stefan Schäfer" >> A : rsgb_lf_group@blacksheep.org >> Copie ā : >> Objet : LF: Cardioid RX antenna for LF... > >> >> Hello Group, >> >> I've just started to play a bit in EZNEC, trying to simulate a receive >> loop antenna for the new YV7MAE grabber. >> http://dl.dropbox.com/u/74746618/LF/YV7MAE_LF_Grabber.html ... still >> using a wire receive antenna with excellent results but now a >> directional antenna is needed. >> >> So i modelled a loop with a possible shape and a ground connection. Then >> i added a R on the far end of the source. The results of the elevation >> and 3D plot are surprising good. Maybe i have done a mistake in >> modelling? Optimal performance was obtained at R = 8 kOhm. This resulted >> in the best F/B and beamwidth... Results of ZENEC are here: >> http://dl.dropbox.com/u/19882028/LF/Cardioid%20for%20LF.png >> >> Any ideas, experiance or advice? >> >> I guess a preamp is needed when such a antenna is used. The typical 1:9 >> un-un does not look useful for me... >> >> 73, Stefan/DK7FC >> >> -- 73 Warren K2ORS WD2XGJ WD2XSH/23 WE2XEB/2 WE2XGR/1