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-   -   21CT55 Screen-Shot Test (http://www.videokarma.org/showthread.php?t=257997)

colorfixer 09-29-2013 07:41 PM

Quote:

Originally Posted by zenithfan1 (Post 3068046)
Hontou ni? Ore wa Samusung no taikutsu:D

nihongo ga sukoshi dake dekimasu...

:lmao:

BigDavesTV 09-30-2013 07:44 AM

Absolutely beautiful screen shots! Such wonderful color rendition, and sharpness! Nah, I'd rather watch a flat screen :-) Haha.....

Sandy G 09-30-2013 08:03 AM

Just kinda says quietly & eloquently that we HAVEN'T really made all THAT much progress in nearly 60 years-Tweaking things a little one way or another, yeah, better reliability-Maybe- but better rendition of color ? Not so much...Leastways, that's the way I see it...

Tomcomm 09-30-2013 05:41 PM

Observed line-pairing
 
Wayne...........Screen-shot # 5 displays only one field not a full frame time. In checking the parameters of that jpg shot I noted it's shutter opening time was 1/13 second or quite sufficient for a complete 1/30 second interlaced frame. It is apparent that line-pairing occurred during screen-shot #5 as you observed. Since all the other shots taken within a few minutes had good interlacing, an anomaly had occurred. Early-on I observed that vertical interlace quality is greatly influenced by the front panel vertical hold manual setting, even when the hold is well removed from causing vertical roll. I considered this imperfection to be of secondary importance and accommodated it by manually tweaking the vertical hold to achieve interlace immediately before any quality screen shot. Apparently, I neglected to tweak the vertical hold before shooting #5. I intend to get into the vertical deinterleaver some day to find out why the waveform differential circuitry is not operating correctly…..Tom

Penthode 10-06-2013 03:20 PM

Interesting about the interlacing. The earlier black and white sets especially from the more expensive RCAs (630TS through 9TC270) had more complicated sync amplification and two sync clippers. Along with the good, more comprehensive vertical sync integration and the standard blocking oscillator, the interlace is generally excellent over a wider range of the vertical hold control. The cleaness of the vertical sync applied to the vertical oscilator is demonstrated when you intentionally roll the picture with the vertcal hold ids a "smooth" roll rather than a "jerky" roll which implies fully stripped sync free from any remaining video.

The mid 50's RCA sets had considerably cheapened sync circuits and disposal of the blocking oscillator transformer with feedback from the output stage expands the problem of oscilator drift from one to two stages. (I however thought the 'CT55 was the last color set to maintain the transformer). Maintaining good interlace would be affected.

It suggests to me that the designers in the mid '50's were on a tight budget to remain competitive. I'd be curious of others thoughts and if others have had the same problem with mid 50's RCA vertcal circuits. (I am currently tracing a vertical sync drift in my CTC5 as the set warms up over 1/2 hour).

old_tv_nut 10-06-2013 07:28 PM

Quote:

Originally Posted by Tomcomm (Post 3083835)
Wayne...........Screen-shot # 5 displays only one field not a full frame time. In checking the parameters of that jpg shot I noted it's shutter opening time was 1/13 second or quite sufficient for a complete 1/30 second interlaced frame. It is apparent that line-pairing occurred during screen-shot #5 as you observed. Since all the other shots taken within a few minutes had good interlacing, an anomaly had occurred. Early-on I observed that vertical interlace quality is greatly influenced by the front panel vertical hold manual setting, even when the hold is well removed from causing vertical roll. I considered this imperfection to be of secondary importance and accommodated it by manually tweaking the vertical hold to achieve interlace immediately before any quality screen shot. Apparently, I neglected to tweak the vertical hold before shooting #5. I intend to get into the vertical deinterleaver some day to find out why the waveform differential circuitry is not operating correctly…..Tom

Line pairing generally comes from horizontal energy getting into the vertical sync - but it doesn't have to be a sync signal separation circuit problem necessarily. It can also occur due to ground currents from the H sweep getting into the vertical, and this can be very difficult to find and fix, as it depends on the physical arrangement of ground points of the various circuits of the chassis. If the sync circuit itself is clean, then experimenting with extra ground leads and lead dress, or actually moving existing ground points may show some effect.

DaveWM 10-07-2013 08:50 AM

I have had my bouts with interlace issues on RCA sets (some same models some fine some more critical on vert hold setting), I have read that the .001 cap often found from the primary lead of the vert out trans to ground (.001) is there to ground horz noise that works its way back from the yoke thru the transformer.

I know I had a BW maggie that had a real bad interlace issue, the sync pulse looked fine, the vert hold could not be set to get rid of it (like most sets). in desperation I switched the yoke, voila interlace issue gone. I cant recall the details that lead me to suspect the yoke (I was scoping stuff and some how noticed hash that seemed to be coming from the vert out trans).

Tomcomm 12-03-2013 07:01 PM

Test big 21CT55 screen shots
 
http://i677.photobucket.com/albums/v...ps4c78518f.jpg

http://i677.photobucket.com/albums/v...psa82bcb96.jpg

http://i677.photobucket.com/albums/v...pseb242eb2.jpg

http://i677.photobucket.com/albums/v...psc8b86c8a.jpg

http://i677.photobucket.com/albums/v...ps54286ef5.jpg

http://i677.photobucket.com/albums/v...ps0a3ed219.jpg

http://i677.photobucket.com/albums/v...psf15525ff.jpg

http://i677.photobucket.com/albums/v...psff15ed5b.jpg

Chip Chester 12-04-2013 08:50 AM

Ferris Bueller, you're my hero.

Cameron

Username1 12-04-2013 09:19 AM

disgustingly good picture..... !

Tomcomm 12-25-2013 03:35 PM

Merry Christmas
 
Enough Ferris Bueller and DVE for a while. Something more seasonal for the 21CT55 to display.




http://i677.photobucket.com/albums/v...ps51058c02.jpg

http://i677.photobucket.com/albums/v...ps8611ce64.jpg

http://i677.photobucket.com/albums/v...ps47174e91.jpg

http://i677.photobucket.com/albums/v...ps5ee2488d.jpg

http://i677.photobucket.com/albums/v...psa6895d88.jpg

Pete Deksnis 12-25-2013 09:43 PM

Great screenshots. The cat jumps right out at you...

Pete

old_tv_nut 12-25-2013 10:09 PM

Wondering why Santa's sweater looks neutral white in the first shot and bluish in the 4th shot. An effect of your camera, or visible to the eye in person also?

RobtWB 12-26-2013 09:49 AM

nice

to my eyes the flesh tones are amazing

Tomcomm 12-26-2013 12:50 PM

Santa Sweater Mystery
 
I re displayed the two Santa s on the 21CT55 and the 27in Sony. The sweaters were identical white with black patterns. there was no bluishtint on either. So there must be some anomaly in the camera ?? I've included the Santa redo and the original video capture jpg that drove the two TVs .

http://i677.photobucket.com/albums/v...ps8d25750d.jpg

http://i677.photobucket.com/albums/v...psd699cf60.jpg

http://i677.photobucket.com/albums/v...ps8ffb662b.jpg

http://i677.photobucket.com/albums/v...psf9e65581.jpg


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