Hello, first post. The audio output of my Grundig digi-box is connected thru the length of the house, to my p.c. soundcard via a category 5 cable. I have a low frequency buzzing sound on the "line in" from the digi-box. It is not there on any other source, just the digi-box connection. I previously tried coax cable which was worse. Help please, where can I look? Note: there is no "earth" connection on the power circuit in the house, could this be the problem? Anything metal I touch (at either end of the connection) is "live", including the lead itself! thanks.