Yes, I've actually tried the DSL filters as a test and that completely wipes out the Terk signal. I know the post sounds rather complicated but there are diagrams out there of how the system is set up; here's a link:
In the diagram it shows the system being connected into the phone line. The other way to hook this system up is to split the signal coming our of the transmitter and to run a separate phone wire to each television that has a receiver. If you take this route you'll still get an awesome picture (more than likely clearer and brigher than the source) and the phone wire is much easier to hide on long runs that a bulky coax cable!
Greg