NOTE: Preamplifiers and/or amplifiers only amplify the signal your antenna receives. A preamplifier is used to overcome any losses in coax cable from the antenna to your TV. They cannot extend the receiving range of an antenna, nor can they help pull in signal. It is not recommended you use the higher gain AP-8700 model within 35 miles of the TV transmitters. When you use a pre-amp you will need a short length of coax cable to link the TV to the power inserter.