I subscribe to DirecTV and my DirecTV set top box was made by Hughes.I
haven't ever noticed it causing any kind of interference.It could be
your Hughes set top box is defective.Mine is sitting on top of a wooden
board on top of my tv set I use for watching old,old movies (Magnificent
Obsession movie is on there now) which is sitting next to another tv set
I use for my webtv.
cuhulin