Museum of the Broadcast Television Camera

RCA TK-10A Television Camera

RCA TK-10A Television Camera and top view of the taller viewfinder with "slats"

Paul R. Beck writes:-
For all practical purposes, the heads are identical. But the viewfinders have significant cosmetic differences. The TK-10 viewfinder has a top section that is a vent with open metal slats. It serves as a sort of chimney for heat rise and from the side view, sticks up about an inch. The TK-30 finder lacks this tall chimney and has a leather-wrapped handle for lifting. Most folks did not carry it by the handle but it was placed there as part of the "Field" designation as dictated by the influence that military design had upon the camera system. I am advised that in early 1947 the field camera system was rushed through manufacturing in Camden, New Jersey, partly to compete with Dumont and GE. Dumont had released their version of the field camera. RCA had problems with the viewfinders and some hard to obtain parts, yet it did not stop them from selling cameras to eager customers in the US, for mobile unit applications. RCA provided a pop-in cover which fit onto the TK-10 head, with the same color and metal fastenings. It came with a flip-up optical gunsite viewfinder frame. It was not uncommon to see a live telecast where only one camera had a legitimate CRT viewfinder, and one or two others had the operators hunched over, peering through the optical site framework. Obviously tough for focusing when changing lenses, but that's what the high fidelity carbon button interphone system was for.

I think by 1948 or 1949, the crisis had passed and all RCA TK-30s were being shipped with a real viewfinder, but they were cosmetically different from the "taller" TK-10 finder.