It's Useless Knowledge

      In the heyday of network radio, NBC's Master Control setup was a technical marvel -- but it looked nothing at all like most Master Control systems of its time, and bears only a superficial resemblance to later systems.  And the engineers mainly just set it up for the next event; the NBC booth announcers actually pushed the button to switch from a show in one studio to a remote or a different studio (or even from Chicago or the West Coast).  They tore it all out when they rebuilt network HQ for television.

      Here it is in 1933:

No pressure, but...remember, the whole country's listening.

      After a lot of digging, I finally found a description of the system, starting on page 22 here.  It's interesting indeed, with 48 (!) different studios and patchable off-site sources feeding eight "busses" that can, in turn, be assigned to any of fourteen outgoing lines.  In the 1930s, NBC was feeding up to five different networks (Red and Blue* were the big ones, Orange and Gold were mostly West coast and at least one smaller regional or special-purpose networks), two owned-and-operated AM stations in New York, plus NBC's own shortwave and experimental FM transmitters.

      There was nothing else like it at the time or later.  Other than possibly a panel or two, there's not a bit of it left, either, and most if not all of the people built who built and ran it are gone.  So figuring out how it worked, even in broad outline, is an interesting challenge. 

      I guess it will come in handy if I ever fall into a time machine.
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* NBC Blue eventually was spun off and became ABC.