Forum: Geek Forum
Topic: elctro magnetic interference
started by: mqa
Posted by mqa on Jan. 24 2001,01:47
i have this md player and from time to time it would skip and act wierd for no reason. just recently i have discovered this behaviour only occurs when i play an md while in my car and driving in excess of 70mph. i know next to nothing about the subject, but i was thinking that the strange behaviour is due to the elctro magnetic interference being put out by my car's engine at that speed. has anyone else noticed a similar phenomenah? do any of you know enough about these matters to explain to me if i am right/wrong?This message has been edited by mqa on January 24, 2001 at 08:49 PM
Posted by cr0bar on Jan. 24 2001,02:27
The problem is your minidisc player. It sucks. Throw it out and get a solid-state mp3 player for way too much money, or be happy with a decent CD player.  In all seriousness though, where the fuck on that island are you driving @ 70mph for more than a few seconds?
Posted by aventari on Jan. 24 2001,02:33
no you car certainly does not put out enough EMI to screw up your miniDisc player. In the old days a cars ignition system used to screw up peoples TV reception as it would go by houses, but alas that is no more. I'll bet your monitor puts out twice the interference of a modern auto. ------------------
aventari
"If God had meant for us to use the metric system, we would have been born with ten fingers and ten toes."
Posted by mqa on Jan. 24 2001,03:38
going over the pali, 70 is my crusing speed.
Posted by masher on Jan. 24 2001,06:03
It is possible that the car could put out some sort of EM radiation that hits a harmonic with your md player.However, it is more likely to be vibrations... ------------------
"All is number" - Pythagoras
Posted by damien_s_lucifer on Jan. 24 2001,06:50
you'd hear EMI in your headphones or speakers long before it screwed up the electronics in your md player. it's almost certainly vibration. it could be that around 70mph, physical vibration hits the perfect frequency to really screw things up.another possibility is something is screwy with your car's electrical system (alternator, voltage regulators) is causing spikes/dips in the power going to the player. Yet another possibility is a ground loop, caused when one of the paths to ground has a significantly different resistance than another path. I had a ground loop once in a speaker connector. If you turned the volume up too high the whole system would squeal. I lost a lot of hearing to that one  is this device mounted in your dash, or is a portable? if it's portable, try holding it in your hand, in your lap, or putting it on a sweater to minimize vibration. ------------------
Vote Republican! It's easier than thinking.
Posted by Sithiee on Jan. 24 2001,08:26
its probably just sub-quality parts with a lack of esp(electronic skip protection) i wish the cd player that came with my car had some esp....ive made it skip so many times with my crazy driving habits...i can also make it skip by smacking the cupholders....theres toyota quality for you..but i cant really complain considering i basically got my car for free(got being an overstatment...borrowed from my parents nearly full time is better)...yup...but it could be something with the md player itself, if its a portable, cause i dropped mine off of my bed (its a loft) and its got this wierd fuckup now, where it skips in random places, when its lying still....i need a new one...
Posted by cr0bar on Jan. 24 2001,13:44
I don't think it's vibration. Try using other audio sources than your MD (I'm assuming you're using a portable MD with a casette adapter for the car stereo). My casette adapter exhibits similar behavior (a buzzing when the headlights are on).Also try adjusting the volume settings. For example, put the MD player on max volume and leave the car's amp relatively low, or vice versa. If you're not using a casette adapter and have an MD unit in the vehicle. . .allow me to snort and laugh at the same time. . .
Posted by kuru on Jan. 24 2001,17:53
it's probably not EMI. how's the vibration in that car when you're doin 70? lotta pot holes?------------------
kuru
'dancing is the vertical expression of horizontal desire.'
-robert frost
Posted by Dark Knight Bob on Jan. 24 2001,21:26
well unless you got and electro magnet strapped to ya dynamo the size of a beer keg (notice how i use alcohol as a descriptive quantity) although depends how you got the bitch plugged in. if its running off the main battery it could be because you got a shit transfromer for your md and the high speed is overloading it somehow.------------------
*This post has been thoroughly checked by highly trained professionals and has been found to be free of alcohol or any other mind altering substance*
Posted by mqa on Jan. 24 2001,23:23
its a portable md w/ a casette adapter, its also internally powered, rather than from the car. it has 20 senconds of anti shock and has never been damaged. the road is relatively smooth, repaved about 2 years ago i think... no potholes. the next time ill be driving on that road is friday night (or early saturday if im lucky) so i will try everyones suggestions.
Posted by CatKnight on Jan. 25 2001,17:16
if its an old car, or a geo or some small-ass wiener car, it's possible that it has to drain more power from the alternator to keep up the speed, which could cause some small power surges in your devices. i know in my car whenever there is a bass drum or low powerful noise, the headlights would dim momentarily. kinda cool actually that my headlights flicker to the beat heheh.
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