Abstract :
The paper describes the electrical and mechanical design of a transmitter suitable for use on a carrier system of wire-broadcasting over the existing telephone network. The transmitter, contained in a standard 6-ft cabinet is complete with power supplies, test equipment, audible and visual monitoring facifities, and power supplies. The output is on eight carrier frequencies at 55, 77, 99, ¿¿ 209 kc/s, at a level of 100 mV per channel with a source impedance of 75 ohms. Plug-in unit construction is used, which together with a selective alarm system, facilitates maintenance of the transmitter. Performance details are given, conclusions experimental transmitter, and some proposals are are drawn from the experience obtained with the made for an improved design.