Electrical transcription

Electrical transcriptions are special phonograph recordings made exclusively for radio broadcasting, which were widely used during the "Golden Age of Radio". They provided material—from station-identification jingles and commercials to full-length programs—for use by local stations, which were affiliates of one of the radio networks.

Physically, electrical transcriptions look much like long-playing records, but differ from consumer-oriented recordings in two major respects which gave longer playing time and reduced likelihood of diversion to private use: they are usually larger than 12 inches (300 mm) diameter so did not fit on consumer playback equipment, and were recorded in a hill-and-dale, or vertical cutting action, as distinct from lateral modulation as in ordinary monophonic discs. They were distributed only to radio stations for the purpose of broadcast, and not for sale to the public. The ET had higher quality audio than was available on consumer records, largely because they had less surface noise than commercial recordings. Electrical transcriptions were often pressed on vinylite, instead of the more common shellac.