Return-Path: Received: (qmail 23361 invoked from network); 4 Jan 2001 00:09:37 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by extortion.plus.net with SMTP; 4 Jan 2001 00:09:37 -0000 Received: (qmail 22415 invoked from network); 4 Jan 2001 00:12:13 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 4 Jan 2001 00:12:13 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14Dxp7-0004gA-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 04 Jan 2001 00:00:05 +0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from d06lmsgate-2.uk.ibm.com ([195.212.29.2]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14Dxp6-0004fi-00 for rsgb_lf_group@blacksheep.org; Thu, 04 Jan 2001 00:00:04 +0000 Received: from d06relay02.portsmouth.uk.ibm.com (d06relay02.portsmouth.uk.ibm.com [9.166.84.148]) by d06lmsgate-2.uk.ibm.com (1.0.0) with ESMTP id XAA83264 for ; Wed, 3 Jan 2001 23:45:21 GMT Received: from usa.net (ss1.bld.socks.ibm.com [9.14.4.66]) by d06relay02.portsmouth.uk.ibm.com (8.8.8m3/NCO v4.95) with ESMTP id XAA71378 for ; Wed, 3 Jan 2001 23:59:23 GMT X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3A53BCBE.706C84C1@usa.net> Date: Thu, 04 Jan 2001 00:58:54 +0100 From: "Alberto di Bene" Organization: Undisclosed X-Mailer: Mozilla 4.76 [en] (Win95; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Gyrators References: <200101031346_MC2-C076-A2B@compuserve.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: "'Geri' Kinzel, DK8KW" wrote: > Alberto I2PHD, > > Alberto, first of all thanks for providing ARGO, I have played around with > it and found it very useful. > > About the coils on 9 kHz: I am using a u-shaped core with a closing bar on > top made of ferrite material (special thanks to Markus, DF6NM). Using this > setup I have a coil wit 1 H (one Henry) inductivity, lifting the ferrite > bar on top by means of a screw some tenth of a millimeter I can fine-tune > this coil between about 0.5 and 1 H. With 10 Watts output I achieve a > current of roughly 130 mA into my 18m vertical ... sufficient for about > 770m distance ... > Hello Geri, thanks. Funny, the two extremes of the spectrum have the same problems of detection of signals below the noise. I was reading a couple of days ago about the experiments done by John K3PGP using a modulated laser light, aimed at the sky. He says that it was possible to receive the scattered light and to recover the modulation at 25 km distance... impressive. This looks as another possible field where QRSS and/or DFCW could be of help.... 73 Alberto I2PHD