Return-Path: Received: (qmail 67479 invoked from network); 24 Dec 2003 22:08:36 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore01.plus.net with SMTP; 24 Dec 2003 22:08:36 -0000 Received: (qmail 43583 invoked from network); 24 Dec 2003 22:08:36 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 24 Dec 2003 22:08:35 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1AZHBD-000BE5-K5 for dave@picks.force9.co.uk; Wed, 24 Dec 2003 22:08:35 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1AZHAf-00041G-PF for rs_out@blacksheep.org; Wed, 24 Dec 2003 22:08:01 +0000 Received: from [212.135.6.12] (helo=smarthost2.mail.uk.easynet.net) by post.thorcom.com with esmtp (Exim 4.14) id 1AZHAf-000417-8t for rsgb_lf_group@blacksheep.org; Wed, 24 Dec 2003 22:08:01 +0000 Received: from tnt-1-90.easynet.co.uk ([195.40.206.90] helo=erica) by smarthost2.mail.uk.easynet.net with smtp (Exim 4.10) id 1AZHAd-000HxF-00 for rsgb_lf_group@blacksheep.org; Wed, 24 Dec 2003 22:08:00 +0000 X-Bad-Message-ID: no DNS (erica) Message-ID: <004101c3ca6c$58838980$5ace28c3@erica> From: "g3ldo" To: rsgb_lf_group@blacksheep.org References: <6.0.1.1.2.20031224113817.0381be40@POP3.freeler.nl> Date: Wed, 24 Dec 2003 22:17:51 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Rope Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.60 (1.212-2003-09-23-exp) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.60 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SPAMFiltered: yes X-Spam-Rating: 2 Dick Rollema said ----------------------- Starting transmitting the aerial ammeter swayed wildly and I heard a disturbing noise outside. It appeared that one half of the aerial had come down. It turned out that one hoisting rope had been burned through where it had passed the pulley. Between the pulley and the "pyrex" insulator had been some 15cm of rope. But it had been raining for several days and the rope bust have been soaking wet. See the attachments; the top end of the rope was on the pulley I intend to replace the rope and to insert extra ceramic insulators of the dog bone type as I have supplied to several British amateurs (they come from the closed down "Radio Kootwijk" commercial PTT-station). ----------------------- I have had this trouble even when using Dick's "Radio Kootwijk" insulators. It only seems to happen where there is a short length of insulated rope between the insulator and the support. What seems to happen is that the insulator eventually becomes dirty (in my case covered with a thin film of salt). This, together with wet weather conditions, produces a conduction path that can carbonise the short rope support. The fix is to use copper wire between the insulator and the support fixing point. After a storm at sea I have seen blue spark tracts running along the salt coated insulator but this arrangement has not failed. However the insulator should be cleaned because such sparking causes minor damage to the surface of the insulator. The problem reported by Dick doesn't seem to happen where there is a long rope from the insulator to the support structure. Peter, G3LDO