Then you can only record the one channel that the tuner is tuned to.
The purpose of MythTV is to have multiple tuners and program it to automatically record different shows at different times on different channels.
Yes, it will work, but you miss 99% of the functionality.
So you add the IR Blaster functionality (a couple of bucks worth of parts at Radio Shack) and have MythTV change the channel on the satellite tuner before recording. :)