This was posted by CPanther95, moderator at AVSForum:
Reports are that there is indeed a kill signal that will deactivate the STB's OTA capability. The kill signal is starting to be sent for early cancellations, so it is, IMO, likely (but not definitive) that they intend to deactivate all STBs (OTA) at the end of the service.
In my view, it would be prudent to disconnect the satellite input prior to 4/30/05 - just to be safe. The earlier the safer.
If you call to cancel Voom service prior to 4/30/05 - DEFINITELY disconnect the satelllite coax prior to making the call.
TIFWIW.