CT-100 S/N B8002601 is Operational

[fujifrontier]

Originally Posted by Tim

Glad you had a great time with your family Pete. Have a good trip back East. Thanks for the encouragement and the club initiation.

I appreciate the sentiment Fujifrontier. Hang in there, there is a whole lot of fun in the quest.

haha, i meant it in much the same vein as a toddler whose ice cream falls to the ground while there sibling munches happily away at theirs :rofl:

[wa2ise]

Originally Posted by Steve D.

Tim,
The moire effect is common with digital screen shots.

-Steve D.

To avoid the moire efects, you'd need to photograph the TV screen at a much higher resolution. High enough that you actually capture all the RGB phosper dots. This also applies to scanners used to scan magazine ads. High enough resolution to capture individual halftone dots. Then using Photoshop or such, do a low pass filter, aka "blur" on the picture. Then shrink the image to the desired final size. Photoshop's shrink is usually preconfigured to do the blur before the shrink for you.

TV camera designers even in the old days had to worry about this. To avoid moire flicker (in interlace mode this really sticks out) they had the TV camera lens designed so it could never make too sharp an image on the pickup tube. The scan lines did a "digital sampling" of sorts of the image in the vertical direction. Have the image too sharp of say a distant window with venitian blinds and some of the slats would fall between the scan lines. And produce moire patterns that don't exist in the real world in person.

[fujifrontier]

hmmm... so what would happen if we fitted a TK-41 with a modern day HD-grade lens? :P

[Bobby Brady]

Originally Posted by fujifrontier

hmmm... so what would happen if we fitted a TK-41 with a modern day HD-grade lens? :P

I suspect a "modern day HD grade lens" is nothing more than a specific style of lens available way back. I don't think modern lenses were any different than the lenses specially designed for the TK-41.

[Bobby Brady]

It is really neat to see special stuff like that when it looks so new.

That is wild that the tube is in such great condition.

Has it had that sealer applied to the metal/glass seam?

Could you tell us about the sets history? I guess someone used it for awhile and put it away for years. It would be very interesting to know why it had little use and how you came apon it.

Perhaps it is in another thread?

It must be a very special sensation to be in charge of something so special.

[fujifrontier]

Originally Posted by Bobby Brady

I suspect a "modern day HD grade lens" is nothing more than a specific style of lens available way back. I don't think modern lenses were any different than the lenses specially designed for the TK-41.

well the reason I asked was because w2aise said

they had the TV camera lens designed so it could never make too sharp an image on the pickup tube

and i thought perhaps todays lenses werent like that

[Tim]

Yes, the vac-seal product has been applied to the seam. It is amazing that some of these CRTs are still good but many have gone to air. It could partially be related to the environment in which they were stored. I believe this set was always kept in a controlled environment where there would be minimal expansion and contraction due to extremes in temperature. I am sure there are a number of factors involved, even the day of the week it was made and the exact manufacturing tolerances of the components.

I do in fact know the history of this set, which is an interesting component of any historical item. I am the third owner (custodian) of it and one of my sons will be the 4th. It was originally owned by Budd Lynch who was the radio announcer for the Detroit Redwings and I believe is now the PA announcer for the team. It had at least one service episode as can be seen on the service tag I posted earlier in the thread. This was in 1956 when there was no vertical sweep. I saw no evidence of what was actually done to repair it.

In 1970, the person that I purchased it from acquired it from the Lynch family. He is a friend of the family and remembers the set always being in the downstairs basement rec room when he was a child.

It was used occasionally by him from 1970 to around 1980 and not turned on after that. It was moved from Michigan to Florida around 2002. I purchased it in 2005. My wife and I drove down to Florida, and brought it back to New Jersey.

It will be in the Living Room of our 1917 home on Christmas to display to the relatives.

[John Folsom]

Tim,
I agree with Pete, the focus control should not be at an extreme end of its range. Check the series resistor (8.2M), and the control itself. And try another focus rectifier, tube testers don't give a very reliable indication of actual circuit performance of HV diodes.

While you will never get the convergence perfect, you should be able to do better than shown in your picture. check the components in the dynamic convergence amp circuit (you probably already have), and keep tweaking it, you will get it better!

The HV performance you are observing is pretty much the way it worked the day it was made. You just have to resign yourself to watching the set in subdued lighting, and NOT be tempted to turn the brightness/contrast up as high as one would expect to.
Keep us posted!

[fujifrontier]

didnt they used to say that you should watch TV in a darkened room anyway? I remember an episode of happy days where mr. cunningham told richie that...

[Tim]

Hi John:

Thanks for the info. It helps to know that that is not normal. I recall the 8.2M resistor was in spec but I do not know what it was. I'll reduce it to the low side of the spec and see what happens.

I have had 3 focus rectifiers in there with the same results. The current one is a NOS RCA. I am thinking that maybe faulty doorknob cap(s) is(are) contributing to the problem? I think I have something I can replace them with as a test. But the replacements I have are old as well.

I have now drunk the potion and adopted the creed of the HV challenged.

[Tim]

Originally Posted by fujifrontier

didnt they used to say that you should watch TV in a darkened room anyway?

My mother always told me I would ruin my eyes if I watched TV in a dark room.

[fujifrontier]

OH no, nevermind, i was wrong. kind of like burning in an image orthicon camera. just that bright TV "square" burned into you retinas.

I had it wrong, I think mr.cunningham was watching a scary movie and turned the lights up because he was scared, and give richie the excuse that "they say you should watch television in a brightened room"

[Pete Deksnis]

Originally Posted by John Folsom

Tim,
Check the series resistor (8.2M), and the control itself.

Thanks John for correcting my mistake. It was written just before a 50-mile trip to the airport in a Michigan, lake-effect snowstorm. Okay, that's no excuse but it's the best I can conjure up for flipping the focus and convergence schematics in my head

[Bobby Brady]

I understand the logic to that idea but does anybody know for sure?
Thanks


Tim, Thanks for the history! How did you come to find the set?

[ChuckR]

Please excuse me jumping into your thread. As a long time lurker, with little technical expertise, but an abiding interest in early color sets, I enjoy reading about your adventures with dirty tuners, fried coils and accidental zaps of HV.

I spent nearly 30 years in the film and television business and was transfering film to video in the mid-70's on an RCA film chain at Compact Video in Burbank that used a 21" roundie for a monitor.

We always viewed color sets in dim rooms. So dim, you needed small lamps to read and write notes. This was true on film chains, with flying spot scanners, when editing, and when I was ending my work life, when I did high def transfers of 35 mm lo con reversals and color correction of 2K digital film files to HD. CRT color sets (and I believe plasma also) are best seen in dim, diffuse light, almost like a movie theater. At least that is what I was taught, and my eyes told me.

And as far as I know, no one ever went blind watching those sets.

If this sounds preachy, please excuse me, but that was my experience.