The preamplifier pole-pond designed for the reception of the satellites APT with NOAA and METEOR VHF in the range of frequencies from 137 to 138MHz. The preamplifier is equipped with band-pass filter with high Q in the input is followed by a stage of the new generation of amplification at low noise figure. The gain of the preamp is 20dB, and there is a relay by-pass to bypass the preamp. And you can feed it via coaxial cable ( must be a bias tee ) or externally through an RCA connector. It is protected from electrostatic discharge, reverse polarity protection and supply disturbances.