Our AA7C has been a favorite for the serious DX"ers, and now it"s even better! It works on all bands - shortwave, HF, VHF and UHF! Imagine a self-contained unit just 4 inches square that pulls in the signals like a 60 foot long wire; that"s the advantage of an active antenna! For jazzing up VHF/UHF receivers and scanners the AA7B has you covered too. Over 15 dB of gain pulls in the weak ones whether you use the included telescopic whip or an outside antenna. Unlike it"s predecessor, the AA7B requires no band switching to cover the range of 1MHz to 800MHz. That"s right, it has a bandwidth of 800Mhz with up to 20 dB of gain at an input signal level up to -20dBm. A pair of N-Channel MOSFET tetrode transistors provide the gain. Because they are tetrode MOSFET devices, the gain adjustment is accomplished using a variable DC control voltage so the gain control potentiometer won"t cause any noise if it gets "dirty." The transistors and solid state relays are surface mount devices, so the signal path (and therefore a lot of potential signal loss!) is minimized. What if you don"t need any gain? No problem! Just turn the AA7B off and the solid state relays automatically route the signal directly through with no amplification and a very minimum, 1dbm or less, of signal loss. There are no mechanical switches in the signal path to get dirty and degrade the signal levels. High quality BNC connectors provide input and output connections to your antenna and receiver Features of the AA7B include: Front panel RF gain control, power switch with preamp bypass switching, rear panel input and output connectors, convenient 9 volt battery operation and telescopic whip antenna (or connect your own antenna with the BNC connector). We think you"ll agree that the AA7B is simply the most practical and best value of any active antenna on the market! Includes whip antenna and matching case set. Operates on a standard 9VDC battery (not included). Case size 5"W x 1.5"H x 5.25"D.