Short-hop radio-relay systems using tunnel-diode repeaters

The first part of the paper considers the properties and design requirements of short-hop radio-relay systems; in particular, systems using nondemodulating, nonfrequency-changing repeaters. It is concluded that a system of close-spaced low-power repeaters, mounted on the towers of the high-voltage transmission network, is technically and economically feasible and would be efficient in utilisation of the frequency spectrum. The second part of the paper describes the design of a 2-way u.h.f. tunnel-diode repeater and its performance in the laboratory and in a short experimental link. The u.h.f. repeater was developed to test the practicability of tunnel-diode repeaters for the short-hop system already considered, but, because of the relatively low aerial gain available at u.h.f., its application is restricted to overcoming obstacle loss between two u.h.f. radio terminals. It is finally concluded that tunnel-diode repeaters are feasible for short-hop systems and could find an immediate application in reducing propagation loss over short but difficult radio paths.