Design of a High Power Single-Sideband VHF Communications System

When high-power transmission is considered in the vhf region, it is implied that ionospheric scatter propagation is contemplated. The type of modulation that best fits the propagation mode is considered-especially fm and SSB. This discussion shows that SSB is a logical choice for this type of circuit and that adequate frequency stability is the only requirement necessary to insure improved communications at vhf using this method of modulation. Some of the factors influencing the design of a 40-kw, duplex, vhf system are presented.