Early Callsigns

In the early days of radio, the NZ Post Office maintained strict control of the operation of police radio transmitters, including the allocation of callsigns. Mobiles used the fleet number of the car, however special callsigns were allocated to the base stations, in the interests of "security". The idea being that anyone who overheard the messages would be unaware of their origin. Police bases stations were allocated Maori Tree Name callsigns;





The obvious flaw in this attempt at communications security was that the messages passed between the "trees" and the cars was in plain languages and dealt with things like burglaries and fingerprints, giving the casual listener a fair chance of identifying the source of the message.
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