Centris, a market research firm in Los Angeles, warns that 5.9 million over-the-air digital TV receivers will lose access to at least one of the major TV networks when analog TV transmission goes away one year from today, the New York Times reported. Many will fall prey to the “cliff effect” of digital signals, which simply disappear from the screen instead of degrading with ghosts, static and snow as analog signals do. Centris said signals in Las Vegas, Philadelphia and St. Louis would peter out 35 miles from the transmitter, not at 60-70 miles as analog signals do. It’s worst in St. Louis, where topography helps block signals for 10 percent of receivers. It’s not as bad in Vegas, where 2.5 percent falter. Though most over-the-air receivers now rely on rabbit-ears antennas, those won’t always do the job. Centris regularly surveys household phone, cable and other subscriptions, DVD usage and other competition, for every census area.