THe HR34/AM21 will only list the channels it can see, and if there are no channels it won't edit them. That's different from the other DirecTV DVRs, which use a database and will try to display all the signals for those channelseven if they are marginal.There is a signal threshold the signal has to exceed before the HR34 will list it. It sounds like your signals might be too low for that, remember the AM21 splits the signal which reduces it by 50%, and that your TV tuner is probably a newer design and more sensitive than the AM21.
What signal strengths do you get on the TV? What's your splitter configuration for your OTA signals? And what's your zip code?
What signal strengths do you get on the TV? What's your splitter configuration for your OTA signals? And what's your zip code?