Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.5.9) with ESMTP id 1163519 for rob@logan.com; Thu, 11 Apr 2002 16:39:40 -0400 Received: from mta6.srv.hcvlny.cv.net ([167.206.5.17]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Wed, 10 Apr 2002 18:57:09 -0400 Received: from optonline.net (ool-18ba44db.dyn.optonline.net [24.186.68.219]) by mta6.srv.hcvlny.cv.net (iPlanet Messaging Server 5.0 Patch 2 (built Dec 14 2000)) with ESMTP id <0GUD0044EJY86U@mta6.srv.hcvlny.cv.net> for lancair.list@olsusa.com; Wed, 10 Apr 2002 19:01:20 -0400 (EDT) Date: Wed, 10 Apr 2002 18:59:07 -0400 From: Adam Molny Subject: Re: Ritchie Electronic Compass To: lancair.list@olsusa.com Message-id: <3CB4C3BB.CD7DF42C@optonline.net> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT References: <20020410041538.AAA519@pop3.olsusa.com> X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> I've been following this thread, and I feel the need to speak out. One builder's teething problems with a particular installation have evolved into an indictment of any electonic device which has not been "blessed" by some self-appointed authority. We must remember that in the experimental community, we are encouraged to innovate and find the better, more cost-effective mousetrap. You do not need to throw out your electonic compass at the first sign of RF interference. There are simple, well-known measures which can be taken to alleviate the problem. Interference can only come from one of two sources: the wiring, or stray RF fields. The wiring problem may be as simple as adding RF chokes (little iron donuts) to the device's power lines. To address RF problems, place your device in a "Faraday cage", which is simply a sheet metal box with as few openings as possible (you may perforate it for cooling). The box acts a ground plane, and effectively shorts out the radio waves which are flying around behind your panel. Whatever is inside the cage sees a quiet RF environment. You can try using aluminum, or for better results, "Mu metal", which has better magnetic properties for blocking RF. This is the same cheap steel they use to make computer cases. In conclusion, don't be afraid to innovate. If we hadn't adapted automotive technology to aircraft use, we would still be flying with magneto ignition, carburetors, and AM radios...wait, strike that last one . -Adam Molny, BSEE Legacy #151 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>