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NTSC Field Test Sets and Prototypes |
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Prototypes A prototype is defined as a set with a metal-cone CRT, or with screw socket mountings, or with no engraved stamping on the chassis, or which would have been made in very small quantities, or has characteristics/circuit additions that would indicate it is an experimental/prototype set.
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1953 G.E. prototype with metal cone CRT (Courtesy of Chuck Azzalina)
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Field Test Sets and Early Prototypes Some of the sets below were Field Test receivers were used in "Field Testing" of the NTSC Standards from late 1951 until May 1953. The NTSC submitted its petition after this testing to the FCC in July 1953.
(RCA prototype photos courtesy of Dave Abramson)
RCA Triniscope #2 (1950) (Danny Gustafson Collection)
TLS50. Based around the CTC-2B chassis (21CT-55), with no modifications to the basic chassis, except to leave off the convergence yoke assembly. All the circuitry associated with the fantastic control panel is passive components, used to adjust the bias on the 3 CRTs, and set up the vertical and horizontal sweep and focus. The projection optics are 3 Norelco Protelgram boxes, with special versions of the 8NP4 CRTs, with blue, green and yellow phosphors, and a red Wratten filter. (Courtesy of John Folsom)
RCA 1949 dot sequential prototype. Three 2 1/2 inch CRTs were used.
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