Quote:
Originally Posted by miniman82
........ Now that I have had a chance to see both wideband and narrowband color sets, I can honestly say that my eye is not sensitive enough to tell the difference. To me, the 21-CT-55 looks just as good as my cheapo Philco 17MT80 if you ignore the Philco's 3.58MHz dot crawl.
I strongly suspect that as soon as I am able to get component input working on the 17MT80, it will rival the perfomance of many higher end units.
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I have been actively modifying my 21CT55 to process external component video since January 2010. The CTC2B chassis seemed the ideal candidate CT since it uses low-level matrixing and has potentially >4mhz bandwidth video CRT drivers. I have progressed to the level of working out all the required interfacing and have constructed one of three RGB channels feeding the three CTC2B CRT driver boards. I have all the notebook entries complete with waveforms to finish the dual composite / component switchover. I have posted my rational for this component video effort on at least three occasions:
10-26-2010 Pete D………. to answer your question: In the mean time, I will use the CTC2B chassis only as a hardware test bed and waveform only monitor for my experiments with external Component video inputs. Seems that the three components: Y, Pr,and Pb, are available on three of my DVD players. Y is the luminance with sync that has no 3.58mhz chroma messing it up so it can extend the baseband to 5mhz which equals over 400 lines resolution, where all our roundys cut off at 3.2mhz or 256 lines! I think I can extend my 21CT55's original final three stages of CRT Drivers to possibly 5mhz without chroma interference. It would be great to see the resolution chart wedge with its lines displayed to 400 lines without all the chroma artifacts we see now. Do any of you see a problem?
01-01-2011 My CTC2B chassis is not constrained by the "restoration" consideration and has never processed the deceased NTSC RF/IF programmed inputs. It has always performed as a pure composite video monitor, driven from DVD, Laser Disk, S-video VCR, C-Band Big-Dish and 4DTV Digicypher. At the time of its flyback meltdown, I was in the process of modifying it to accept Component Video which should extended its baseband luminance and chrominance to a full 5mhz or 400 lines vs the 3.3mhz or 264 lines of NTSC Composite Video. Now if only I can get a replacement flyback that would converge as good as my original CTC2B, I can proceed.
04-08-2011 Since my 21CT55 is not an original RCA restoration but a "laboratory test-bed", I saw no reason to copy RCA's external video input circuitry using early '50s technology. Instead, I implemented a solid-state video op-amp that provides a "perfect" DVD quality 480 line resolution, 75ohm , 5vpp signal into the 55's 1st video amp grid. It also supplies the same 75ohm video at 1vpp to my two comb-filtered Sony monitors and a Leader waveform monitor. Two external video sources can be selected with a toggle switch, each with individual level and offset controls. Presently I run a DVD player with the DVE test disk into one input and a second DVD player with program disks or OTA HD converter into the second input. Now that the 21CT55 's PQ is at least as good as it was before the tragic FBX meltdown I intend to resume my implementation of 480 line component video processing in addition to the present 280 line composite processing, hopefully.......Tom