The AP8700 and similar preamps from competing vendors provide a means to send power up the coax from a power supply, located in a convenient and protected location, to the actual amplifier unit which ideally would be located within a few feet of the antenna.
This photo from Amazons add shows the amplifier (largest component), power transformer and power inserter (smallest component). Perhaps you could describe your arrangement in more detail, so we clearly understand were you have each component located and how they are connected.
Again, a precise TVFR would be helpful.