Radio interference

I have an inexpensive Sony hu and I routed my usb charging cable behind the surround and up to the phone holder. I can’t stand loose cables at the dash. Problem is when the phone is plugged in there’s rf interference.
Any ideas how I can shield the charging cable to eliminate the static?

 

First make sure the HU and the charging cable (I assume from the 12v outlet / cig. lighter) share the same physical ground point. If not run a new ground between them and go from there.

 

i've had this problem a number of times in my work van, usually a coworker brings a phone charger with, and we can't enjoy the afternoon radio commercials the whole way home.

try a different usb charger. they're all cheap, but some of the super-cheap one's tend to emit more RF than others.

 

Toroids. They stop RF from getting into the cable. Electronic store or maybe even an audio shop.

 

Been away. Thanks to all.
I'll check the grounds first.