Re: Radio Static With Engine RPM
From what I've learned the hard way:
ANY noise connected to bad ground or not-enough-isolated wires can and MUST be found & repaired without buying noise filters. If the noise is from the bad gnd/bad isolation, then no noise filter in this world will solve it. First, and best thing you could do is to make the GNDing wire as THICK and as SHORT as possible! That (gnd) wire picks up the noises that come from plugs/plug wires/alternator. The longer the wire, the bigger the noise. Plus, those other wires mentioned above by some fellow Jeepers need to be changed (spark wires, and basically all the "red" (hot), high-tensioned wires are suspects. The "greater" tension wires first, so that's why it's usually the spark wires, or the alternator wires. So, DON'T run your radio GND from the engine compartment, there's no need. Instead, ground it as close to the radio as possible. Make it a good, fat, clean contact. Then check plug wires, alternator (+) etc.
I bought filters & filters, put them zillions one behind another, I even built my own filters. What the noise filter does is a high-cut: it cuts out high frequencies (which you hear as whining noise). But that way you either kill power flow to the radio (which you will notice as radio-lights dimming to the beat), or if you put that hi-cut filter in series with the speaker, it'll kill most of the highs in the spectrum, leaving you just with a lot of bass & low-end mids (not nice, actually [img]images/graemlins/puke.gif[/img] ).
Als, if you have an amp...They tend to create such whining prbs. They can, and absolutely MUST be GNDed short & thick.
So, in my oppinion, after checking all the wires & finding nothing (experience [img]images/graemlins/crazy.gif[/img] ), go & get some well isolated wires to hook up the radio. And some nice, fat, StarTrek-style-isolated speaker cables. Once you get'em, they'll last almost forever, in every case longer than any car you might put'em in, so you'll always be able to transfer them somewhere else.
BTW, wanna hear some serious whine? We here use (90%) the FM waves. Switch to AM or MW area, and tune to empty (where is no station). There you go, some SERIOUS whining.
Or put in the blank casette & hear the "silence" (everything BUT silence). There you get all the "failures" to show.
Up to date, I didn't find the way to kill it. Not that I use anything but CD & FM, but...