RCA TK-42 (1962–1971)
A four-tube color camera that helped push television into color — and then pushed engineers to the edge of their patience.
Overview
By any measure, the TK-42 is a big camera. The television camera museum's own description puts it plainly: "a big 4 tube camera by any standards." It's a live color television camera built by RCA, and it belongs to that fascinating early-1960s moment when broadcasters were being dragged — sometimes reluctantly — into color.
The TK-42's story doesn't start cleanly. According to the eyesofageneration.com account, RCA debuted the first version of the TK-42 in 1962, "but it wasn't in its final form and in production until '65." Grokipedia, meanwhile, gives the introduction as "around 1964" in one place and "around 1965" in another — a contradiction on the same page that says something about how muddy this camera's timeline really is. What's clear is that it took years to get right, and RCA's own broadcast newsletter admitted as much, noting that only "a little over a year ago we started shipping in quantity."
The design itself was RCA's attempt to solve the central problem of color television in the mid-sixties: getting a sharp, bright picture out of tube technology that was still fighting for enough light. The TK-42's answer was to add a fourth tube. In addition to the usual complement of three tubes for the red, green and blue images, a fourth tube was included to provide luminance detail of a scene. The Valve Museum's account explains the reasoning: "the four tubes allowed designs with better registration. The TK-42 used the 4.5 inch image orthicon to provide high resolution luminance information."
Key Features
Three Vidicons and a 4.5-Inch Image Orthicon
The heart of the TK-42 is its tube complement: a 4.5 inch image orthicon tube for the luminance and 3 x 1 inch vidicons for the three colours, as the camera museum describes it. RCA's own broadcast newsletter put it a little more awkwardly — a "4 tube camera, with 4% inch I.O. luminance channel, and 3 vidicons," an OCR artifact that should be read as 4½ inches. The Facilities CAMERAS history phrases it as "combining three vidicon tubes (red, blue, and green) with an image orthicon (monochrome channel)."
That image orthicon was a specific, interchangeable part. According to the RCA 4536 datasheet, the tube is an "Image Orthicon 4-1/2-Inch Diameter Type. For RCA TK-42 and TK-43 TV Color Cameras," and "Type 4536 is Unilaterally Interchangeable with Types 4492, 4492V1." That interchangeability matters for anyone keeping one of these alive — the tube is shared with the TK-43, which widens the pool of spares, at least in theory.
Built-In 5:1 Zoom Lens
The camera came with a built in 5 to 1 zoom lens, per the Facilities CAMERAS history — and its photo caption notes the built-in zoom explicitly. A built-in zoom was a real convenience in an era when many cameras still relied on turret-mounted primes, but the TK-42's zoom arrangement became one of its most notorious liabilities. The original rear-control design proved impractical, so the zoom and focus were run via cables to conventional controls on the starboard and port pan handles. Those cables had a tendency to crimp, and that would cause the zoom mechanism to stick, or "chatter." Camera operators, in the words of the Facilities CAMERAS history, were "frustrated by the chattering zoom lenses."
Pedestal Mounting and a Bigger Steering Ring
The camera would fit onto the standard Houston Fearless electric pedestals, but a new, larger control ring was needed for steering. That's a small detail that tells a larger story: the TK-42 was heavy and awkward enough that the existing hardware had to be adapted to it. It was, however, "lighter in weight" than its TK-41 predecessor — a relative claim, since the absolute figure of around 280 pounds excluding ancillary equipment comes from a single source (Grokipedia) and should be treated as approximate.
Dimensions and Light Hunger
Grokipedia gives dimensions of approximately 23 inches wide, 16.5 inches high, and up to 45 inches long when equipped with a viewfinder and lens adaptor. Those numbers are unconfirmed by any second source, so take them as reported rather than verified.
More consequential is the light requirement. The TK-42 required almost twice as much light as the older black and white models. 250 foot candles was the norm and in some situations even more lighting was required. In a studio, that means heat, power draw, and talent squinting under a wall of lamps. It's the kind of spec that explains why the camera's reputation soured as newer tube technologies arrived.
Historical Context
The TK-42 arrived into a market RCA largely owned. Its predecessor, the RCA TK-41, had been the world's standard for live color, according to RCA's broadcast newsletter — a tough act to follow. The TK-42 was an entirely new design, more transistorized than its TK-41 predecessor, and it was meant to carry that standard forward.
It didn't go smoothly. The eyesofageneration.com history is blunt: "Unfortunately, the TK12/TK60 problems were the beginning of the black eyes for RCA that landed in mass with the TK42." The same account notes that "NBC never used the RCA TK42 or 43," and that with an aging fleet of TK-41s in the field, NBC ordered 35 Norelcos to their own specifications. The timing was brutal — 1965 was also the year Norelco introduced its Plumbicon PC60, a tube technology that would make the TK-42's vidicon-based color look dated almost immediately.
RCA's factory struggled to keep up regardless: according to big13.net, it "struggled to meet with the demand of 300 cameras in 1966." Stations did buy them. WTVT in Tampa received four RCA TK-42 color cameras as part of its color conversion in June 1966, and by 1970 those cameras had been in use for five years. When WTVT's chief engineer replaced them with four G.E. PE-400 cameras — arriving in December 1970, premiering in January 1971 — the TK-42s were donated to WEDU-TV, the local PBS affiliate. Other documented uses include a TK-42 at WCEE-TV that went on the air in 1970, and RCA TK-42s at WBTV-TV's "Boys Town Auction" in Charlotte in 1972.
Collectibility & Value
Here's the honest part: there is essentially no collector market data for the TK-42. No current prices, no maintenance or repair procedures, no spare parts availability — none of it turned up in the research. What does exist is a reputation. Engineers were fed up with the TK-42's high maintenance issues, and the chattering zoom lenses drove operators to distraction. The vidicon tubes produced a somewhat plastic color picture when compared with the images produced by the Plumbicon-tubed Norelco PC-60 — a comparison that would have stung at RCA in 1965 and still defines how the camera is remembered.
Surviving units are rare and mostly institutional. One TK-42 at WSLS 10 in Roanoke received a cosmetic overhaul as part of an open-house celebration — a restoration of appearance rather than function, which is about what most of these get today. Anyone contemplating one should assume the image orthicon and vidicons are the hard part, and that the zoom cabling will need attention before anything else. The camera is a piece of broadcast history, but it's a piece that fought its operators every step of the way.
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