A prototype design for microprocessor based digital telemetry transmitter for low frequency data

A prototype microprocessor based digital transmitter with low power requirements has been designed and built for use in dial-up telemetry applications. The processor used is the 8 bit RCA COSMAC. Input data is an analog signal in the range of -5 volts to +5 volts which is digitized to 12-bit precision. The transmitted data is a serialized and encoded frequency-shift-keyed signal suitable for transmission over phone lines or radio. Over 500 16-bit words can be stored in the data buffer for transmission with expansion up to 8k words possible. Average power consumption is less than 100 ma at 5 volts.