On (22 Jan 95) Jason Lavoie wrote to All...
 JL> that is a 3 pin BNC connector and has A.I. marked next to it... 
(auxiliary 
A BNC connector has a pin in the center, a collar around the pin, and
a bumb on each side of the collar leading to a spiral track.  Cables
are pushed into place, then given a turn to lock them down on the
bayonet.
If your connector has three pins in a circle about 1/2 inch (1 cm) in
diameter, with a projection that you can push in to unlock the cable,
it's a Cannon XLR connection.  This type of connection is most
commonly used for microphones (Audio Input?) or for power supplies. 
If you have a microphone you could afford to lose, you could plug it
in here; if the camera provides sound as well as picture, the
connection was probably an audio input; if it goes up in smoke,
perhaps the plug was to provide power to accessories for the camera!
There's no such thing as "a 3 pin BNC connector."
... Notice: All incoming fire has the right of way.
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