iPhone radio interference
I've got a cassette adapter in my trusty old truck so I can listen to music on my iPhone while driving to the dump. The only problem that I have is from radio interference that is transmitted through my speakers. This is especially noticeable when using Edge or Bluetooth. It's less noticeable when using 3G. Since there is plenty of Edge remaining in my neck of the woods, it would be nice to somehow filter out this interference.
After spending some time with Google, I have yet to find a solution to this problem. Does anyone know if there is a filter I can purchase - or some other solution to this problem? I was thinking that there ought to be a filter between the iPhone and the input line to the cassette adapter. When I use my phone in the aux port in my car, or connect with my car's bluetooth system, I have no interference. This leads me to believe that it has something to do specifically with the cassette adapter. My concern is that it's not the input line, but the magnetic nature of the cassette player itself. If this is the case, am I SOL?