The end of the line

Discussion covers base station antennas in the 25-50 mc and 148-174 mc bands. Various types and combinations of antennas are discussed which produce shaped horizontal coverage patterns for non-circular areas so as to concentrate the radiation over the desired area. This approach to coverage is both economical from an investment standpoint and tends to reduce interference to other users. Directional antennas with deep nulls on the back or side are effective in reducing co-channel, skip, desensitization, inter-modulation, and transmitter noise types of interference. Better utilization of the sides of towers can be obtained by the use of side-mount antennas to obtain either circular or eccentric horizontal patterns. This permits greater antenna gain than otherwise possible and also allows a number of systems with sufficient frequency separation to occupy the same tower structure.