Radio Shack amplifiers are my least favorite... My experience has been that almost all are plagued by noise and distortion problems compared to similarly priced amplifiers. But... before you bother with an amplifier, you need a signal worth amplifying, that's the job of a properly selected antenna that's mounted where it has access to receive a usable signal. Amplifiers are a bit like well pumps, a 100 psi pump and a 40 psi pump will both fail to deliver water when they're installed in a dry hole. And neither pump would deliver drinkable water if they leaked oil or lead into the water they're pumping.
If I was in your position, I'd be focusing on WHSV, real CH-42 which carries ABC, Fox, MyN, Me-TV and CBS (per rabbitears.info). Your 100' TVFR suggests the signal is not that hard to receive once the antenna is high enough... I'd check to see if less than 100' is able to provide a LOS path. I'd be looking at tree mounted options or a tower. If those options aren't feasible, I'd look at the option of a remote receiver,
http://forum.tvfool.com/showthread.php?t=1286.