UHF Radio-Relay System Engineering

UHF radio-relay transmission is affected by atmospheric conditions, obstructions, distance, antenna height, and path clearances. It is important that paths be engineered with adequate clearance. A nomograph is presented for rapid determination of the required clearance from path parameters and operating frequency. Various types of transmission paths with means of minimizing fading are discussed, and a method is derived for determining from the path profile the required spacing of receiving antennas for space diversity. A single-hop system is evaluated in terms of equipment parameters and displayed on a level diagram. This is followed by a discussion of the system performance and reliability of a number of hops in tandem.