Return-Path: Received: (qmail 6242 invoked from network); 29 Jun 2001 13:09:34 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 29 Jun 2001 13:09:34 -0000 Received: (qmail 13928 invoked from network); 29 Jun 2001 13:08:34 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 29 Jun 2001 13:08:34 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15FxuN-0001UR-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 29 Jun 2001 14:02:03 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from [167.142.226.22] (helo=smtp-out.netins.net) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15FxuK-0001UM-00 for rsgb_lf_group@blacksheep.org; Fri, 29 Jun 2001 14:02:00 +0100 Received: from netins.net (desm-32-118.dsl.netins.net [167.142.32.118]) by smtp-out.netins.net (8.9.3/8.9.3) with ESMTP id IAA24492; Fri, 29 Jun 2001 08:01:17 -0500 (CDT) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3B3C7C1B.E1D89D99@netins.net> Date: Fri, 29 Jun 2001 08:01:15 -0500 From: "Dr. Tom Gruis" Organization: =?iso-8859-1?Q?www.gruis.org_&_K=D8HTF?= X-Sender: "Dr. Tom Gruis" <@smtp.netins.net> (Unverified) X-Mailer: Mozilla 4.76 [en]C-gatewaynet (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Lightning -- Knife Switch Source References: <200106290250_MC3-D77E-9595@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: I have read that these old knife switches have very poor RF insulation qualities. Perhaps this effect is frequency and/or power sensitive (for want of better terminology) to some extent. Doc. "Holger 'Geri' Kinzel, DK8KW" wrote: > > Tom, G3OLB: > > >Years ago I remember my grandfather having a wireless aerial (as it was > >known then) down his garden which came through an insulator in the > >window frame and was connected to a ceramic knife switch on the window- > >sill. This allowed changeover of the aerial from the wireless to earth > >during thunder storms. Does anyone know of a source of such switches > >these days? > > ... have a look at > > http://www.surplussales.com/Antennas/Antennas-4.html > > ... the second item is similar to the switch that I use to ground my > umbrella antenna whenever not in use. Is this the kind of switch you are > looking for? > > Best 73 > > Geri, DK8KW (W1KW)