Return-Path: Received: (qmail 20274 invoked from network); 8 Jun 1999 21:30:10 +0100 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by guiness.force9.net with SMTP; 8 Jun 1999 21:30:10 +0100 Received: (qmail 4258 invoked from network); 8 Jun 1999 20:34:45 -0000 Received: from punt.unica.co.uk (194.75.183.60) by magnus.plus.net.uk with SMTP; 8 Jun 1999 20:34:45 -0000 Received: from troy.blacksheep.org ([194.75.183.50] ident=root) by punt.unica.co.uk with esmtp (Exim 2.00 #2) id 10rSUP-0007q9-00; Tue, 8 Jun 1999 21:28:53 +0100 Received: (from root@localhost) by troy.blacksheep.org (8.6.12/8.6.12) id UAA12073 for rsgb_lf_group-outgoing; Tue, 8 Jun 1999 20:27:31 GMT Received: from post.thorcom.com (root@post.unica.co.uk [194.75.183.70]) by troy.blacksheep.org (8.6.12/8.6.12) with ESMTP id UAA12069 for ; Tue, 8 Jun 1999 20:27:28 GMT Received: from tk2.ihug.co.nz ([203.29.160.14] helo=smtp2.ihug.co.nz) by post.thorcom.com with esmtp (Exim 2.04 #3) id 10rSh1-000809-00 for rsgb_lf_group@blacksheep.org; Tue, 8 Jun 1999 21:41:56 +0100 Received: from test (p33-max2.chc.ihug.co.nz [207.214.13.33]) by smtp2.ihug.co.nz (8.9.3/8.9.3/Debian/GNU) with SMTP id IAA15688 for ; Wed, 9 Jun 1999 08:26:21 +1200 Message-ID: <001e01beb1ed$3a2325a0$0b0dd6cf@test> From: "Dave Brown" To: rsgb_lf_group@blacksheep.org References: <3.0.5.32.19990608151030.007a0100@zen.co.uk> Subject: Re: LF: Noise update Date: Wed, 9 Jun 1999 08:26:31 +1200 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2314.1300 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Another possibility for the ultrasonic rx that I have used successfully for the same purpose is a standard gas leak detector as probably used by BT cable jointers etc. Controllers for strings of street lights have been occasionally notorious here too. Dave ZL3FJ