Thanks Ewe - the interference is confirmed as coming from an Alpha XM2 cable head end "switched mode sort of" 60V PSU unit anout 1 Km from my home - The interference is common mode on the coax distri
congrats Laurence, so one problem has gone. I have got home made problems: feed back from the transmitted signs into the sound cards Im using. so Im playing around with groundings and shieldings. GL