And I must ABSOLUTELY quote "A Premade one can be bought for under $20. But wheres the thrill of making something yourself with that?"!!! Are we the same person?
Btw, I'm not really a "poor man", and I don't think that everyone having enough money and effort to spend in a carputer is a REAL poor man, but I simply LOVE the challenge of efficiency. I always want to obtain the best results with the smallest effort... And I succeed most of the time! Sorry for you guys that prefer to buy premade things, paying more and learning nothing, but I'm a geek and I'm proud of it! Well, actually I'm not a real geek, since I have a girlfriend, but who cares!
PS: my circuit is wrapped up in 19 cent red electrical tape...
Old Systems retired due to new car
New system at design/prototype stage on BeagleBoard.
You will be surprised to know that in the past i even wond (mmmh... past of "to wind"? sorry for my english.....) my own transormers...
worked nicely for me. I already had a ground loop isolator (from radio shack) b/w the computer and both amps, but I was getting a loop b/w the sub amp and highs amp. I installed this b/w the 2 amps. Worked great!
Celeron 2.53 Ghz Processor
512M ddr memory
Mimo 7" USB Display
XM Direct Tuner
mp3car.com XM Direct USB interface box
1999 Mustang GT Convertible Supercharged
I had tons of problems with the generator noise, and had tried a lot of stuff (but apparently gone in the wrong direction). Then finally turning to the net (where I of course should have started) I found this, which works perfectly! Thanks a million man!
Arg! I just threw away two modems I had kept for the longest time. I have tons of parts that I finally decided to organize and consolidate. The only stuff I chucked were the modems and an 8MB graphics card. I should have known better. I like your tutorial and would have preferred to build the isolator over junking the parts. Never fails when you decide to chuck something
sorry to disagree with the solution.
telephone/modem coupling tranformers are good only for telephony,
that mean they are made for telephony bandwidth : 300-4000Hz
below and above this range, nothing is guaranted and the cheaper the device, the narrower its frequency response.
Did you measure 20Khz and 20Hz output levels compared to a reference @ 1KHz ?
I might be making a big assumption but I would have thought that the interference noise had a relationship to the RPM of the engine, in which case the telephony bandwidth is almost perfect - I guess it could go a little higher