Back in the day when there were no cart machines, Reel-to-reel players, CD players or computers to put audio onto the air, Turntables were the mainstay in the business.
Of course in radio's infant days, all programing was done live; all music was done live by studio orchestra's hired for that purpose. Then in the early 1930's turntables popped up in radio stations and by the early 1950's most local radio stations programing emanated from turntables whether it was music, pre-recorded commercials or promo's; hence came the rise of the Disc Jockey.
In the 1950's most radio stations, except those in very rural areas utilized the services of engineers to operate the technical equipment and they and the disc jockey's worked as a team. This included the use of turntables to spin the records; some stations had arrangements where the disc jockey spun his own records; others had union contracts that required either the engineer or turntable operator to operate all technical equipment including turntables (Chicago was notably different in that the musicians from the AFM had to operate any turntable playing back music)so the engineers became old friends of spinning records on the air.
By the end of the 1970's, most radio stations, except those in major markets had eliminated the use of engineers for operating on-air technical equipment and the job fell into the hands of the disc jockeys.
One of the most well-known turntables made for broadcasting was the RCA-70D Turntable; Of course other companies such as Fairchild and Gates made 16 inch turntables but the RCA-70D was the beast of the radio industry; utilizing a 16 inch felt covered platter; 2 pickup arms and 4 speeds (that's right; 33 rpm; 45 rpm; 78 rpm and 13/16ths rpm)plus pickup selector and an in-line equalizer. It was a gear driven affair that took a full turn to get up to speed.
A good on-air engineer or disc jockey worth his salt would cue up the record and "slip cue" it as opposed to backing it up one complete turn before turning on the juice to it. Slip cuing gave you a tighter sound and less chance of having the record "wow" in before it achieved speed.
One of the redeeming qualities of the 70-D was its RCA Victor Pickup head for the use of 78 rpm and 16 inch vertical transcriptions so often played back to air. They had that nifty equalizer built into the turntable and all you had to do was select the proper filter mode and you could really make almost any poor sounding record good enough to meet broadcast standards. The other pickup arm was used for
For many years these faithful workhorses served broadcasting well; then the advent of idler wheel turntables made the scene; they got up to speed quicker then the old RCA's and in time they were replaced with direct drive turntables. The old RCA's, much like an old abandoned car, were wheeled into storage rooms and left to collect dust.
When I went to work for NBC Radio back in 1979, they were still using a few of the 70-D's but were being rapidly replaced with direct drive turntables. By the end of 1980 there were no more 70-D's left in service at work. I recall one of my assignments during the summer of 1979 was to, with the help of another engineer, wheel about 20 of those 70-D's down to the sub basement and push them off the loading dock into a waiting dumpster. What a waste of technology and engineering; they no longer make turntables that I'm aware of to play back vertical transcriptions or 78's so those turntables are worth a small mint to collectors; I saw in EBay about 5 years ago one of the 70-D's for sale to the tune of $13,000!
Very few radio stations or recording studios have them anymore which is a shame since its very tough to find one to play a transcription on if you want to listen to one. The exception to this rule is WBXO Radio in Beekman New York; they have not one but two working 70-D's. Still in their RCA "Battleship Gray" cabinets, these work horses continue to plug along as needed and they are well maintained; you'd think they were just unpacked from the crate from RCA. Nice to see these historical beasts still in service in radio.
