What is a Transcription Turntable

The term has been co-opted over the years to mean simply "high fidelity", but originally it was a turntable that could play 16-inch transcription discs common from about the mid-1930s to the late-1940s for radio station use. These 16-inch transcription discs were cut at 33 1/3 rpm and could hold about 15 minutes of continuous playing time per side (as contrasted with 5-7 minutes for 78s regularly played in that period) and were often used for syndicated programs or government broadcasts. Most radio stations had equipment on which they could cut their own transcription discs of programs or for spot commericials. Some transcription systems encoded the signal in a side-to-side playing groove, but at least one used vertical grooves requiring a separate tonearm/cartridge. Thus, the tables often accommodated two arms.
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Wow, Rushton. Excellent post--thanks for the info.

Thanks Rushton that is an excellent piece of history. Much appreciated

Glad it was helpful - my father did work for radio stations for many years, and I remember seeing these big rigs when I got to travel with him (all sitting idle by that time in the early 1960s). Here's a picture of an old RCA transcription turntable:

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