RECEIVERS FOR THE PROPOSED CARFAX TRAFFIC INFORMATION SERVICE
M Bailey · 1978
The paper describes the operation of prototype receivers for the proposed BBC carfax information service. This service entails a dedicated network of medium-wave transmitters all sharing the same frequency, disseminating local information in well-defined service areas surrounding each transmitter. The well-defined forms of the service areas are achieved by the use of special receiver-activating fm coded signals preceding each traffic transmission, together with signals from the surrounding transmitters. Receivers can be arranged to interrupt normal in-car listening for the reception of a information announcement. The paper describes how such receivers are simple to operate and are potentially low in cost. (a) (TRRL)