Quote:
Originally Posted by Penthode
I found this on the ETF Website:
During late 1935 and early 1936 RCA manufactured a few nine-inch field test television receivers, including the RR-359 in our collection. The RR-359 started as a 9-inch mirror-in-the-lid set... Initially the set scanned 343 lines (interlaced) and had a continuous tuner capable of tuning 40 to 90 MHz which frequencies include the current low-band VHF channels 2 to 6 and below to the now defunct channel 1...
In 1937, RCA and other experimental broadcasters moved up to 441-lines, AM sound. This was the RMA (Radio Manufacturer’s Association) standard at the time. It is probable that RCA transferred its old call sign W2XBS for these broadcasts. Programming was extended to include pickups remote from the studio. NBC’s mobile television vans, then a great curiosity, appeared on the streets of New York for the first time on December 12, 1937.
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Penthode,
I actually provided much of the info for that article
While the RMA didn't officially adopt the 441 standard until 1937, RCA was using it exclusively from mid 1936 on.
The original letter kicking off the RR359 project is dated November 25 1935. It states that the first sample should be completed no later than December 24, 1935 for evaluation. These first sets were 9" and used the then current 343i format. These 9" sets were only used for the first few months of testing and most were retrofitted with 12" crt's. The 12" versions of the sets, the RR359B's used the 441i standard. Because most of the 9" sets were retrofitted to 12", very few of the 9" sets exist today. The main chassis and power supply were all that was salvaged from the 9" sets. The cabinets and crts on the 12" sets were all new. The various RR359/B's went through many design changes like a continuous tuner to a detent tuner, higher bandwidth IF modules, a change from A306 prototype IF tubes (similar to 6D6) to communication style 1851's, dual 42 horizontal output tubes to a single 807 along with a change in the horizontal output transformer, seven knob control panel to three knob (they moved the position and size controls inside the set). these sets were built very modular so that sections could be easily updated or replaced.
From R.R.Beal's article in the Journal of the Society of Motion Picture Engineers July 1936: "These receivers have been used to produce two sizes of pictures. For the first few months of the tests, the picture size was 5 1/4 by 7 1/2 inches. At the present time most of the receivers have Kinescopes that produce pictures 7 1/2 by 10 inches in size. Fig. 18 shows a 9-inch Kinescope that produces a 5 1/4 by 7 1/2-inch picture. A Kinescope of 12 1/2 inches in diameter is required to produce a 7 1/2 by 10 inch picture."
The first formal display of these sets to the general press took place on November 6 1936. The sets used in this demonstration were all of the newer 12" variety. This was done both because the 12" crt and 441i format represented the state of the art at the time for RCA, but also because the earlier 9" versions used the 1800 crt which produced a yellowish-green image which had been noted as less than optimal for use for the general public.
Darryl