Transistorized Circuits For Telemetry

This thesis is concerned with the telemetry of small DC signals from photomultiplier tubes. The circuitry must have a high input impedance so as not to load down the photomultiplier tube and a low output impedance which is capable of controlling the current through a small incandescent bulb. This bulb is used to illuminate a photoresistor. The output of the circuit consists of a variation of the resistance of the photoresistor. This variable resistance is conventionally converted into a variable audio frequency which is transmitted to the receiving station on a radio-frequency carrier. The output resistance must be independent of all supply batteries because pf battery consumption during the flight, and the entire circuit must be independent of temperature changes because of the low temperatures encountered at high altitudes