Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (September 2004, week 2)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Wed, 8 Sep 2004 15:03:29 -0700
Reply-To:     Rocket J Squirrel <j.michael.elliott@ADELPHIA.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Rocket J Squirrel <j.michael.elliott@ADELPHIA.NET>
Subject:      Re: Using FM stereo for film soundtrack: tach effect
Comments: To: Zach White <zwhite@DARKSTAR.FROP.ORG>
In-Reply-To:  <35B9E9AA-01D1-11D9-A2E9-000A95E06FE0@darkstar.frop.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Yeah, if the iBook is not just connected to the aux inputs, but is also getting DC from the vehicle, you could have some kind of big loop antenna. As Zach sez, try running the iBook off its batteries and see if the sensitivity to ignition noise is changed.

Mike "Rocket J Squirrel" Elliott 71 VW Type 2 / 84 Westy: A poor but proud race. KG6RCR

Zach White wrote:

> On Sep 8, 2004, at 17:42, Scott Norville wrote: > >> I sat down to ask a question and found this similar stream. I have a >> Panasonic CD player installed, it has a front-mounted aux. jack. This >> works >> great for the DVD on the iBook with the van parked, idling (or coasting >> downhill with the engine off...) but I get too much ignition >> interference >> (whine that increases frequency and intensity with with engine speed) >> with >> the engine running. Anyone know of any type of shielding for this >> function? >> > > Scott, > > That sounds to me like a ground loop (Not the right term when dealing > with a DC system, but same basic concept, IIRC). If you've never had > to track one down, you're in for a lot of rewiring. Even if you have > had to track one down, you may be in for a lot of rewiring. :) > > The suggestion to try swapping the cables between the laptop and stereo > is good, as it's cheap and easy to do, but my gut feeling says that's > not the problem in this case. You should also try another audio source, > such as an ipod or portable cd player. Again, a long shot, but cheap > and easy to check. If the problem still persists, keep reading. > > The first thing to do is to check all the connections on your stereo. > See where it's pulling power from, try running the stereo on only the > "hot" wire (the one that actually powers the system, not the one that > supplies constant power for the radio's settings). See if your speakers > are wired with a common ground or if they have a separate ground for > each speaker. Some stereos want the ground to each speaker separate, > some want it to be common. My van came with the speaker grounds wires > all tied together, I'm not sure if this is common in vanagons. > > You may also try running the stereo directly off the battery, see if > that corrects the problem. > > Replace the wires between the speakers and the stereo. This is not easy > to do in the case of the rear speakers, however. You might try running > just the front speakers, if the problem goes away, you know where to > concentrate on. > > If none of that works, the next thing to check is your ignition system. > Make sure all connections (especially the coil to cap and cap to plugs) > are tight, the wires good, etc. While you're there, apply some > dielectric grease, which will help suppress RFI and help the connection > last longer. > > If none of that helps, you have two possibilities. One is that your > stereo isn't properly designed to keep out RFI. It sucks, but it > happens. The other is that you have wires that are shorting somewhere > they shouldn't be, commonly a ground shorting to the chassis in the > wrong spot. Normal visual checks and troubleshooting procedures for the > electrical system apply here. > > Finally, the problem may be poor ground connections. Check the ground > terminals behind the fusebox, make sure they're clean and you're > getting good ground there. Run the ground for the stereo straight to > the battery, sometimes that will clear up the problem. Some people > don't recommend this for various reasons, but sometimes it works, and > personally, I can't see any reason why you shouldn't do this. (Someone > please correct me if you know _why_ I'm wrong, here.) > > This probably isn't what you wanted to hear, but installing "shielding" > is actually harder than this, when done right. Plus, the stereo is > already shielded, but because something in the wiring is wrong, the > shielding is being bypassed. More shielding won't really help. > > -Zach >


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.