WABC-key station of the Columbia broadcasting system
01 January 1942
General layout and circuit principles of this medium-wave station. High efficiency is aimed at throughout, at the expense, where necessary, of appearance, and the 50 kW output stage operates at 75% efficiency. The station is built a mile out to sea to minimize ground losses, and aerial design provides max. low-angle radiation. A standby 5 kW unit is available in case of breakdown: this normally drives the main amplifier stage. Vital circuit components are duplicated, so that reliable 24 hr. service can be attained. Two high-fidelity under-water cables serve for programme transmission, with a standby 335 Mc./s. link in case of failure of both of these.