Return-Path: Received: from imo26.mx.aol.com ([198.81.17.70]) by truman.olsusa.com (Post.Office MTA v3.1.2 release (PO203-101c) ID# 0-44819U2500L250S0) with ESMTP id AAA4193 for ; Sat, 26 Sep 1998 12:57:51 -0400 Received: from ReganRanch@aol.com by imo26.mx.aol.com (IMOv16.10) id 8IUTa02302 for ; Sat, 26 Sep 1998 12:57:33 -0400 (EDT) From: ReganRanch@aol.com Message-ID: Date: Sat, 26 Sep 1998 12:57:33 EDT To: lancair.list@olsusa.com Subject: Electrical Noise X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Scott asks: <<-have you added anything to your solenoids, and do you think they really need anything?>> On the coil side, definitely. Use a MOV (see other posting) -if you could add anything, what exactly would you add to them so I could order them from an electronics shop.>> See other posting. <<-did you add anything to your alternator for noise? anything else you fell is really needed?>> Controlling noise is best done at the source (You can't fix diarrhea by fooling with the plumbing in the bathroom). Unfortunately there are no pat answers to fix noise. Each source has to be addressed individually. Motors with brushes make a lot of noise so capacitors (to reduce brush arcing) can help here. A significant portion of alternator noise is generated by the regulator contacts opening and closing so I would definitely use a linear regulator (B&C for example). Wire routing and layout is also important. Keep noisy lines together and away from audio or COM antenna lines. One trick is to run power and ground to a noisy source as a twisted pair to reduce radiated noise. This works because a wire carrying a current has a circular magnetic field around it (like your fingers around a rope) so when it is put next another wire with the same current but in the opposite direction, the two magnetic fields cancel each other. Twist the wires using a power drill until you have about 4 twists per inch and if you reverse the drill a little before you unchuck (dechuck? upchuck?) the wire it won't tangle on you. One fellow I know wired his plane with all the power lines down the left side and all the grounds down the right. VERY BAD IDEA as this forms a giant loop antenna with all the electronics in the middle. He was (is) plagued by noise problems and I am afraid he won't be able to fix them unless he rewires the plane! Hope this keeps you current. Brent