[mythtv-users] Question regarding "-1" / HD channels on DirecTV

[Robert Kulagowski]

I can see from http://www.directv.com/sports/nhl_schedules that SD
content may be on channel 771, and HD is on 771-1.

If you're trying to change the channel to the "-1", are you actually
sending a "-1"? Or do you have to lock the STB so that it's in HD
mode, and when you change to 771 you're automatically tuned to 771-1?
Or is it something else?