Rca Tk-41

[firenzeprima]

It would be interesting to know if there are color camera TK 41 still running, and maybe some pictures of them, as for color TV SET CT 100. Someone may say something?

[John Hafer]

This is a great thread! I just have to jump in here after reading all the posts. I am an old color TV fanatic and have been interested in color broadcast equipment for years. I remember back in 1966 that I could actually tell, by the quality of the color image on our color TV, what brand and model color camera a station had. The TK-42 always had a very grainy and low contrast image. I could not believe how degraded the picture was compared to the TK-41. It was no wonder that NBC refused to use them.

I could also tell GE PE-250, Norelco PC-70 and Marconi MKVIII from their pictures.

Another interesting point is that back in 1965 RCA came out with a color film camera version of the TK-42. It was the TK-27 and also used 4 tubes, (in this case 1" for Red, Green, Blue, and 1 1/2" for luminance vs the 4 1/2" IO luminance tube in the TK-42). This film camera replaced the outstanding TK-26 (3V color) camera. The TK-26 was the color film camera used with the TK-41 live color camera.

Again, I could tell from watching a film if the station had TK-26 or TK-27 color film cameras. The TK-26 gave a snappy crisp color picture while the TK-27 made all films look low contrast, and grainy.

I remember back in the fall of 1964 watching the show 'Flipper' and how beautiful the color always looked. Then starting in the summer of 1965, the show all of a sudden had poor contrast, and a grainy image. The deep blues of the water lacked contrast. A few other NBC shows also suddenly started looking that way. I thought something had happened to our TV but later I realized that NBC must have installed at least one TK-27 and was using it for some of their color film broadcasts. Not sure if they pulled the camera later on or not, but the older tube TK-26 produced such a better picture than the "New Look" transistorized TK-27. I bet NBC felt the same about the TK-27 as they did about the TK42.

I read that ABC and CBS both installed GE PE-24 4V color film cameras for their network broadcasting.

[W.B.]

Originally Posted by John Hafer

Another interesting point is that back in 1965 RCA came out with a color film camera version of the TK-42. It was the TK-27 and also used 4 tubes, (in this case 1" for Red, Green, Blue, and 1 1/2" for luminance vs the 4 1/2" IO luminance tube in the TK-42). This film camera replaced the outstanding TK-26 (3V color) camera. The TK-26 was the color film camera used with the TK-41 live color camera.

Again, I could tell from watching a film if the station had TK-26 or TK-27 color film cameras. The TK-26 gave a snappy crisp color picture while the TK-27 made all films look low contrast, and grainy.

I remember back in the fall of 1964 watching the show 'Flipper' and how beautiful the color always looked. Then starting in the summer of 1965, the show all of a sudden had poor contrast, and a grainy image. The deep blues of the water lacked contrast. A few other NBC shows also suddenly started looking that way. I thought something had happened to our TV but later I realized that NBC must have installed at least one TK-27 and was using it for some of their color film broadcasts. Not sure if they pulled the camera later on or not, but the older tube TK-26 produced such a better picture than the "New Look" transistorized TK-27. I bet NBC felt the same about the TK-27 as they did about the TK42.

I read that ABC and CBS both installed GE PE-24 4V color film cameras for their network broadcasting.

Dennis Degan took photos of NBC's setup at 30 Rockefeller Plaza in New York during the mid-to-late 1970's, and they had banks of TK-27 film chains. That might give you a hint as to NBC's attitudes towards the TK-27. Ed Reitan's color TV site mentioned that at least one ABC studio (their Prospect and Talmadge studios in Hollywood), as of the mid-1960's, had had TK-26 film chains, then got TK-27's whose performance had the exact same issues you spoke of, and reverted to the TK-26's thereafter.

It also seemed that on replications of slides, the reds on occasion looked rather weak when compared with the earlier TK-26's - never mind GE's PE-24 (and later PE-240) film chains. I wonder if you could tell by quality which stations used GE PE-24's vs. which ones used the TK-27.

Norelco (of PC-70 fame) had their own film chain, PCF-701 (which used - surprise, surprise! - 3 Plumbicons), but would anyone know which stations, if any, used that particular machine?

[John Hafer]

W.B.

I have seen those photos from NBC and the captions indicate they upgraded their telecine rooms in 1976.

RCA indroduced their 4-tube TK-27 color film camera in 1965 and then replaced it with an improved 3-tube version, the TK-28 in 1972. The TK-28 was a much improved version film camera and by looking at the pictures, and by the date the room upgrades were made, these look like these were TK-28 cameras, even though the caption says they were TK-27 cameras.

The TK-27 had a large camera module mounted on the top front of the cabinet that was visible, where as the TK-28 had a small one or non at all.

Telling which stations used either GE PE-240 or RCA TK-27 film chains was easy! I lived in Boston in the mid 60's and it was easy to tell who had what by just watching some films on their stations.

WBZ-TV ch. 4 and then WKBG-TV ch. 56 had TK-27s while WNAC-TV ch.7 and WSBK-TV ch.38 had GE PE-240s'. WJAR-TV ch. 10 Providence also had TK-27s.

I also lived in Syracuse, and and WSYR-TV ch. 3 went with TK-27s, while WHEN-TV ch. 5 and then WNYS-TV ch. 9 went with the GE color film chains.

The hard part was trying to see the difference between the older RCA TK-26 and the GE PE-240 cameras for both had great pictures.

I read in several sites were the TK-42 and TK-27 cameras just did not live up to the expectations they had hoped, and that RCA later replaced them with the TK-44 (live) and TK-28 (film) cameras which from what I read, were excellent cameras.

Just my comments. Maybe someone else has some better information.

[W.B.]

I noticed the photographer misidentified the TP-7A slide projectors as TP-6's, now that you mention it. So if NBC did have TK-28's as of 1976 and he called them TK-27's, well . . .

As for WNAC-TV using PE-24's (as I saw in GE ads from 1964-65 - they might've added some PE-240's to their roster of equipment after 1966), they were in good company with other RKO stations: WOR-TV (Ch. 9) in New York, KHJ-TV (Ch. 9) in Los Angeles, and WHBQ-TV (Ch. 13) in Memphis also used these GE film chains in their respective setups.

And I wouldn't be surprised that WBZ-TV would've had TK-27's; sister station KYW-TV in Philadelphia also used them. (Whereas WFIL-TV, known after 1971 as WPVI-TV, had PE-24/240's.) As for WKBG: Would anyone know if the use of those TK-27's crossed over to the station's 1974 call letter change to WLVI? It would seem that those TK-27's also had horizontal linearity issues, along with the other bugs you mentioned.

[Telecolor 3007]

Is true that "R.C.A." TK-41 needed to reach stability and they needed a lot of light in order to deliver a good image?

[old_tv_nut]

Originally Posted by Telecolor 3007

Is true that "R.C.A." TK-41 needed to reach stability and they needed a lot of light in order to deliver a good image?

The recommended level for the TK-41 was about 400 foot-candles (4300 lux). Later ultrasensitive image orthicons could reduce this by 2:1 or more.

All photoemissive photocathodes were temperature senstitive and sensitive to their history of use. It seems that any substance with a low work function (gives up electrons easily from light stimulation) was also not chemically very stable.

The image orthicon secondary emission target performance was also temperature sensitive, and subject to burn-in of images.

[claudiogi]

Hello !
Firenzeprima please conctact me, in private, for questions on TK41. I'm working in RAI.

My email is: c dot girivetto at rai dot it

No spam please !

thanks !

[old_tv_nut]

I just acquired a set of DVDs of the Dean Martin Variety Show, which was shot with TK-41s. The remastering seems to have somewhat high saturation, but otherwise looks good.

The thing I wanted to note is the frequent use of a wide-angle lens with the camera close to the performers for head/shoulder shots. I have noticed this on many programs of the time, and I don't know if it was done because of studio space constraints or as a deliberate method to make the relationship of camera and performer more intimate, but it definitely does that. When Dean gestures toward the camera, the perspective change in the size of his hand is quite large, and I think having the camera so close encourages the performers to talk to it like an individual person.

There apparently was much less use of zoom lenses at the time, and I have actually seen dolly shots where it was obvioius that a wheel had developed a flat spot, and the camera "nodded" slightly, periodically, as it rolled.

Anyone having insight on the evolution of camera/staging techniques over the years, I'd love to hear it.

[bozey45]

Cranes were used on the variety shows a lot, Sing Along with Mitch for instance made extensive use of TK-41's on cranes as evidenced by viewing his program. Cranes quite often passed thru the entire group as they did their sing along segment.

[Dave A]

Following focus on a wide-angle is easier for a close-up shot with these old fixed lenses on a turret. And the depth-of-field is much wider allowing the grand sets to stay somewhat in focus. Not as touchy as a longer lens which was probably near wide-open even with the massive lighting. A longer lens would have a more narrow depth-of-field and turn the background quite soft. And a 200lb camera is not helpful either to smoothly move, even if stationary, at a further distance for the close-up.

In my TK-42 days, I quickly learned that to do any kind of dolly move, I did it with the lens zoomed wide and moved the camera to make the shot. Not the lens to make the shot.

On the BW cameras of the day, focus was approximately set on the lens (front-focus) and the op actually moved the IO via the camera focus control for back-focus. Not knowing for sure, but the TK color cameras had to have a similar system. Please correct me if needed. To this day, we still have a front-focus/back-focus adjustment on modern cameras and lenses.

On turret-style cameras, these were the days before motorized iris controls so it was film-style lighting. The lighting director, who was king on any production right after the director, determined a common iris stop on all the lenses in the turret depending on the "look" of the production and poured on the lighting to get the video level needed. Nice and bright for Dean Martin. Darker and shadowy for Peter Pan (which was more of an ensemble production and not inclined to close-ups). Today, this is almost a lost art in television lighting. Auto-iris killed this. Not sure if the early zoom lenses had iris motors.

Many cameras will have a chin light mounted under the lens and that works best up close to hide the wrinkles. You can see these in many old photos. And you also get the cue cards closer to the talent. Helpful if they are getting older.


Dave A

[old_tv_nut]

Color camera optics including the TK-41 and later could not possibly do operational focusing by moving the pickup tubes - there is just too much that has to be aligned and bolted down so that registration doesn't get disturbed. So, operational focus had to be via the front-end. On the TK-41 with multiple fixed lenses on a turret, I believe operational focussing was done by moving the whole lens drum in and out. I don't know what adjustment was available for back focus. Regarding the iris, the TK-41 had a motor controlled iris in the relay lens path, which IIRC limited the maximum opening to F/4. (I'm out of town this week, so can't refer to the literature.) My understanding of how the optics worked was that it didn't matter if you opened the objective lens beyond f/4, f/4 is all you got due to the relay lens - so I'd guess the objectives lenses would all be opened further than f/4 to make sure they weren't affecting the iris adjustment. Unless, of course, one of the lenses was smaller than f/4, in which case I guess you could do it two ways: set all of them to the same smaller aperture, if you wanted consistency, or set all to max aperture, if you wanted the max sensitivity each could give (up to f/4).

[kx250rider]

I believe there's a working TK-41 in a private collection in Tujunga, CA.

Charles

[Sandy G]

Originally Posted by kx250rider

I believe there's a working TK-41 in a private collection in Tujunga, CA.

Charles

I'd give my Eyeteeth...Have absolutely no use whatsoever for one, lack the technical skills to keep one working, no real room to store/display one, but I'd STILL love to have one...Maybe someday Julian will cabbage on one, & I can go down & "love" on his, & get it out of my system...I just think they're kewl as all get-out. Always have, even when I was a widdle kid & would see one on TV...I've seen studio cameras since then, & even have owned a couple of industrial cameras, but it ain't the same thing...Those big ol' grey, humptyback beasts say "Color Television" in the same way a Roundie does-everything that came after is sorta a pretender to the throne. Or am I being silly as usual ?

[Aussie Bloke]

Originally Posted by Sandy G

I'd give my Eyeteeth...Have absolutely no use whatsoever for one, lack the technical skills to keep one working, no real room to store/display one, but I'd STILL love to have one...Maybe someday Julian will cabbage on one, & I can go down & "love" on his, & get it out of my system...I just think they're kewl as all get-out. Always have, even when I was a widdle kid & would see one on TV...I've seen studio cameras since then, & even have owned a couple of industrial cameras, but it ain't the same thing...Those big ol' grey, humptyback beasts say "Color Television" in the same way a Roundie does-everything that came after is sorta a pretender to the throne. Or am I being silly as usual ?

Not at all in my opinion. Nothing beats having the original TK-41, the FIRST TV camera to be used for official colour broadcasting, well not the first, there was the TK-40 but anyways the TK-40/41 cameras are a must have for anyone into broadcast television history and to have them in working order would be mind blowing!!!

I personally have some 70s industrial Sony cameras myself including a 1974 colour Sony DXC-1200P camera http://www.labguysworld.com/Sony_DXC-1200.htm which I plan to restore with online technical help. I could go out and get myself a handycam but I think it's more fun to use an ancient colour camera made before I was born today, I love to shoot the modern world through the eye of a camera that's decades old, I get so much thrill out of it. It's a pity Australia got colour way too late, I would of loved to go trekkin around Australia tracking down TK-41s and roundie colour TVs.