EMI 1936 Emitron Television
Camera
The 1936 camera with the short neck length
Emitron tube. The small hole in the bottom of the casing is for the
talkback headphones.
During 1937 they were all modified to accommodate
the long neck version of the Emitron tube.
At least one was unmodified to
the long neck tube state as late at Nov. 1937 when it was used at
the Lord Mayors Show in conjunction with the new Super
Emitron camera.
Source: Wireless World November 18th. 1937 page 498.