I advised not to use a amplifier , reason , so you would not hook up a high gain amplifier and hurt your chances of reliable reception.
Winegard has a new antenna system amplifier that has Very Low Noise and moderate gain , the Winegard 'Boost' LNA-100.
If you like , you can try the LNA-100 and see if it helps or hurts reception.
http://www.winegarddirect.com
http://www.solidsignal.com.
http://www.amazon.com.