Speech-input equipment for new Oslo broadcasting house

Describes in detail with studio plan and block switching diagrams the layout of the building, method of programme switching and signalling circuits. In both cases automatic methods are used throughout, e.g. four digits are sent to select a programme, the first indicates the input channel number, the next two give the studio number and the fourth the microphone number. Very stringent precautions limit noise and crosstalk to 130 db below zero level; 4- and 8-channel control desks are used, programme and signalling equipment being located in opposite pedestals to limit interference. Amplifier characteristics throughout the chain are flat within 1 db from 30 to 12 000 c/s with 0.2% distortion for microphone and 2.0% for recording amplifiers. A general description of adjustments and procedure and photographs of equipment are given.