Bell Telephone Laboratories conducted experiments with "Two-way Television" culminating with a demonstration on April 9, 1930.
A "phone call" was held between the 195 Broadway headquarters and the BTL facility at 463 West Street in New York City, as representatives of the press looked on. Signals were sent over normal phone wiring, suggesting that distance was not a limiting factor.
It was noted that while interesting, commercial prospects were "uncertain."
Behind each booth was a room full of complex electrical and mechanical equipment, including water cooled neon receiving tubes, rotating scanning disks and racks of gear. The bandwidth required for thousands of stations was well beyond the capacity of existing exchanges.
(Photos from The Northwestern Bell, May 1930.)
|A. W. Horton and M. W.
Baldwin, BTL engineers, monitoring circuits in the equipment room.
Control for the television and telephone apparatus required three racks.
There were also three large cabinets containing the neon tubes, scanning disks and arc light.
|Water-cooled neon tube used
for receiving television images.
In operation, the central rectangle glows with a pinkish light.