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Old 02-12-2018, 05:35 PM
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R.C.A. TK42 versus TK41. R.C.A. TK42 versus Norelco PC-60 and 70

I've read on the forum some time ago that the operatores preffered "R.C.A." TK41 color studio camera in stad of TK42, throu all that TK42 was more modern... but TK42 had Germanium tranzistors, so it was more instable.
But how the image provided by TK42 was compared to the one provided by TK41?
On this site they are saying that C.B.S. had a feud with "RCA" because of the color televison sistem (the electronic color television sistem of the "R.C.A." won) and when "Philips/Nolerco" camed with color cameras they where glad to get color cameras from them. How the image provided by "Norelco" PC-60 and 70 was compared to "R.C.A." TK41 and 42. "Norelco" used Plumbicon tubes ("Philips" invented them).
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Old 02-12-2018, 09:00 PM
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I'll let someone with direct experience comment on the picture quality of TK-42 vs. TK-41.

The improvement of Plumbicon cameras over image orthicons was particularly in the signal-to-noise ratio. While the Plumbicons had inherently lower detail contrast, their high SNR meant that much stronger image enhancement levels could be applied to compensate. The image orthicon noise spectrum was flat white noise from the beam current shot noise. Plumbicons had target capacitance that was compensated by a feedback arrangement in the pre-amp stage, which meant that the 6 dB per octave roll-off of the target capacitance was compensated by a 6 dB per octave rise in the amplifier frequency response. As a result, the noise spectrum also was triangular, with a 6 dB per octave rise; that is, the low frequency noise (which is most visible to the eye) was much lower than the noise of an image orthicon camera.

By the way, solid state sensors have a flat noise spectrum, but it is much smaller than the image orthicon (since there is no constant beam current, plus the quantum efficiency of solid state sensors is up to ten times better than that of photo-emissive sensors), and generally smaller than an equivalent Plumbicon (since there is no 6dB per octave compensation required).
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Last edited by old_tv_nut; 02-12-2018 at 09:06 PM.
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Old 02-13-2018, 07:58 AM
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The biggest problem with the 42's (and 43) was the pin board construction. There was even a bulletin out to resolder all the ground connections (the square pads) on the modules.
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Old 02-17-2018, 08:13 AM
kf4rca kf4rca is offline
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CBS must have had 41's.

Looks like the graphic artists used what they knew for a design for their "please standby" slide.
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