John, the filter is about 6 feet or so from the shed itself but the radio is all in all about 10 to 12 feet from the filter.  I still have the noise even when the pump is off but it could be like someone else said.  Maybe some of those chokes would help.  I'll have to order them because we don't have a radio shack all that close to where I live.  There is one within about 20 miles but the people aren't all that helpful.