The Channel Master television antenna booster (preamplifier) will amplify digital and HD signals received by your antenna. This antenna amplifier is a high gain, low noise preamplifier used for weak signal areas to allow a weak signal that is present at the antenna to be amplified to a viewable strength. The CM 7778 preamp offers less gain than the CM 7777 but still has enough gain to get the signal from the antenna to the TV set. This preamp is a perfect choice if you are in a strong to medium strength signal area but are still having troubles receive the strongest signals. Preamplifier are also used if you anticipate distributing your signal with a digital splitter to multiple locations throughout your location as splitters reduce the signal strength per output.