These amps take an antenna or cable TV signal and boost its strength. The channels on the coaxial cable (whether digital or analog) are Radio Frequency (RF) signals. The amplifiers simply boost the signal level. These signals may be digital, high definition, ATSC encoded, or they might be standard definition, NTSC encoded channels. The amplifier doesn't know or care. It doesn't look at the individual signals, it just amplifies them all.
