I have a DirecTV H20 with an antenna pointed toward Tucson to receive those channels, but have never had any real problem getting any of the South Mountain sticks, save for the occasional issue with 15. 7-1 has come up on my guide for a few months now, but as recently as today I can't get anything to come up. Not even a searching for signal message. Just blank. Do I need to look for Channel 27, or will it map down to 7-1? I'm a little confused.
You would have to go through local channel setup and start all over again by entering your ZIP codes and such. the DirecTV receiver will scan every broadcast frequency to correspond to the virtual number. But, if you antenna is pointed toward Tucson and you're in the east Valley, it might not work, given that the power on KAZT-CA DT is much less than that of the other DTV's from South Mountain.