Pre amps do not improve the gain of an antenna they only keep weak signals from dropping off once they leave the antenna. this is a common misconception. if you have 9
db from antenna it only maintains the 9db to the tv. the 7777 has only 2.0 noise on UHf where the 8800 is 2.8 this is were they differ UHF is more susceptible to noise than VHF because it is a weaker signal.