The 7777 is part of Channel Master's high-performance Titan 2 series of mast-mounted preamplifiers. It is an ultra-low-noise, ultra-high-gain design that can solve a number of reception problems, and is especially effective for long-range "deep-fringe" applications. Several Crutchfield customers have reported that they are receiving digital stations from 50+ miles away using the 7777 in combination with Channel Master's 4228HD antenna.
Two-piece mast-mounted preamplifiers have an advantage over more typical one-piece in-line units because the amplifier module is mounted near the antenna itself, to eliminate amplification of any noise or interference in your coax cable. A preamplifier can improve reception whether the problem is weak signal strength at your antenna, or loss of signal quality due to a long cable run between your antenna and TV.
Installation is simple: run a length of RG-6 cable from your antenna to the 7777's amplifier module, and another RG-6 cable from the amp to the 7777's power supply. Power is provided to the amplifier via the RG-6 cable, so no other wiring is necessary, and the power supply can be placed indoors to avoid exposure to the elements. Finally, run a length of RG-6 from the power supply either directly to your TV, or to a video distribution hub.