Welcome to ReplayTV.
First the ReplayTV tuner is not ATSC, you will need an external ATSC converter box if you are in the US or Canada.
Second, the guide data provided by the standard replay service does not include the ATSC channel data. For that you will need to setup something to provide the data such as WiRNS on a PC. WiRNS can obtain the data by using Schedules Direct or data from a scraper program.