i've been struggling withhs problem for quite sometime now, and have yet to find a way to fix it. The minidisc changer I have in y glovebox is using an rather old Sony FM Modulator. It works but I get that high pithes crackling radio frequency interference. I can't seem to get ridof it with this particular FM modulator. Does anyone knwo where I might be able to find an FM Modulator that will work properly with this mididisc changer? Just in case someone knows, the model number for the changer is MDX-65. Thanks in advance.

your power lines to or from the modulator have to be close to some other power wire thats what is causeing the noise