The "Vagabond" wireless microphone system

A cable-less microphone system has been developed, Designed for general public address use, the system utilizes inductioncoupling between the transmitter and receiver, and requires no license. The subminiature transmitter is completely contained in a stick type microphone housing. It consists of a microphone, a five-tube, printed circuit frequency-modulated transmitter, a self-contained antenna inductor, and batteries, and weighs less than one pound. The system gives excellent performance with operating areas up to 5000 square feet. The development of the system and of the subminiature transmitter is discussed and the performance of the induction system is evaluated.