Return-Path: Received: (qmail 12300 invoked from network); 2 May 2000 08:31:13 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by redlabel.core.plus.net.uk with SMTP; 2 May 2000 08:31:13 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12mXzN-0002Pl-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 02 May 2000 09:25:05 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from irwell.zetnet.co.uk ([194.247.47.48] ident=root) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12mXzD-0002Pe-00 for rsgb_lf_group@blacksheep.org; Tue, 02 May 2000 09:24:55 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from central.zetnet.co.uk (central.zetnet.co.uk [194.247.47.20]) by irwell.zetnet.co.uk (8.9.3/8.9.3/Debian/GNU) with SMTP id JAA20762 for ; Tue, 2 May 2000 09:24:41 +0100 X-ZSender: g3ldo@zetnet.co.uk Message-ID: <2000050208250568199@zetnet.co.uk> Date: Tue, 2 May 2000 08:25:05 +0100 To: rsgb_lf_group@blacksheep.org From: "Peter Dodd" X-Mailer: ZIMACS Version 1.20c 10000836 Subject: LF: Re: Telsa Coils Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-type: text/plain; charset=windows-1252; format=flowed MIME-Version: 1.0 Content-transfer-encoding: 8bit Yesterday, Monday, I operated from GB2CPM, not on LF but at the HF permanent amateur station that forms part of the radio section of the museum. At the Electricity Hall a group of Telso Coil builders had converged for a Telsa coil session. This comprised two groups, an indoor exibition using small coils ranging from 10cm long to 1m long; and the second group with the big coils (up to 2m long) which had to be done outside because of the very high voltages they produced. The indoor goup had the advantage having a large room that could be darkened allowing the spectacular display to bee seen to its best advantage. The room had to be ventilated between sessions to clear out all the ozone! The outdoor group set up a test area in the afternoon, starting by digging a cruciform shaped trench and laying down a lot of copper tubing and soaking it in brine before filling it in. The components of three large coils arrived in special vans and I was able to watch and photograph these coils and the electrical control and power systems being assembled. The length of the main coils of the larger Telsa machines ranged from 1 to 2m with a length/diameter ratio of around 3:1. The inductance of the main coils ranged from 400mH to 1.2H depending on the size of the machine. All coils seemed to be close wound with 1mm enamelled copper wire. The primary coils were made of 10mm copper tubing with clip connections for 'tuning'. This main set of experiments had to be done after the museum had closed to the public and when it was getting dark. The corona discharge from 1meV machine was truely spectacular and made our hair stand on end! I was much taken with the technology of these machines, particularly the care with which the coils had been wound and the construction of high capacity high voltage capacitors. Some members of the group were interested in our activities in a similar technology. If you want to know more about the Telsa Builders activities see -- Regards, Peter, G3LDO