With the recent sale of a Col-R-Tel for $4,000, I thought it would be a good idea to add the surviving units to our Color Database:

http://www.earlytelevision.org/color_database.html

Please let me know if you have one, or know where one is.

Thanks

[email protected]

One Col-R-Tel here with me...in need of a drive belt. Working until the belt went last week. Mounted on a Philco 12".

Dave A

There is a collector out in Riverside, CA, who got a set of electronics from me to complete his Col-R-Tel. There is also a Col-R-Tel (wheel & motor but no electronics) in Orange County, CA with a non-collector. Those are the only ones I know of.

Charles

Here are some pictures of a new Col-R-Tel in the box.

Darryl

pictures of a new Col-R-Tel in the box.Thanks for the pictures Darryl. Wish I could time warp back to '58 and place an order.

Second the thanks for the pix

Actually, even though this unit was originally shipped to my back yard in Lansing MI, I got it from Harry Poster a few years ago, so you never know what still might show up!

Darryl

Here are some pictures of a new Col-R-Tel in the box.

Darryl

I'm curious about the excess red plastic sticking out the edge of the wheel. Was the wheel made by sticking colored plastic on a clear disc?

The red plastic is just stuck to the back of the housing with some black mastic. (you can see it near the ends) It is not part of the wheel. I have not noticed this before on other Col-R-Tel's, but it appears to just be a mask to block something behind it when you are viewing the wheel in operation. I doubt this was added later as the connectors have never been plugged on to the wheel (no marks), the wires were never soldered and the hardware and brackets are still wrapped, so the unit has never been run.
Does anyone know what this might have been for?

Darryl

Mine has a flap too:

http://www.earlytelevision.org/col-r-tel.html

It covers the controls of the set behind it - just an aesthetic touch.

Thanks Steve! Now I see it poking out on your wheel in that picture. I hadn't noticed these before, but it seemed to just be a mask. Sort of a "loud" color for a mask :-O

Darryl

Darry,
I guess they had a lot of red, green and blue filter material at hand. I think I would have picked the blue material for that application. My Col-R-Tel shows no signs of having a flap, but it was old and very used by the time I acquired it.

Has anyone been to this site before or know who's behind it?

http://www.experimentaltvcenter.org/index.html

Video History Project:

http://www.experimentaltvcenter.org/history/index.html

They have an article on the Col-R-Tel:

http://www.experimentaltvcenter.org...p3?id=11&page=1

...

Colordaptors were home made, with some of the parts available from the designer of the unit:

http://www.earlytelevision.org/colordaptor.html

Yours is the third surviving Colordaptor I've heard of.

I have recently gotten the colordapter set, need technical papers, Does anyone have this?? Is this tech info published in SAMS?? Please let me know. What is the rectifier tube used for the color conversion unit?? I have proof my set reproduced a correct color image, he shot some pictures long time ago when set was built showing a great color image on film.

:scratch2:

The original design was published in the January and February 1956 issues of Radio Electronics magazine. Specialized parts were sold by the Colordaptor Co. of Menlo Park, CA, who also provided a manual for its assembly. There was never a Sams folder on the set.

Thanks, I just realized had it in my tech library.

:yes:

I have a real nice Col R Tel but no electronics. Anyone know of one available? Julian

After several years of working on this beast, it is looking good...for what it is. As my girlfriend calls it, "the twirly set".

The B&W set behind it is a Philco 50-T1402 tabletop on an original stand. All restored. I have had the wheel for about 7 years and it too is electronically restored with the help of at least 3 good friends. Recently I took the wheel apart and steel wooled the commutator and secured the brushes when the video started looking noisy. All of this in its original condition

The last piece was the rubber drive belt. After 50 years it gave out. Attempts to glue/melt/staple the belt did not work. One of those friends had found a perfect replacement and it did the trick. Along with some light machine oil on the hub. It is very quiet once it gets up to speed and locked after only a minute or so.

It is now stable and has been running during two Phillies games the last two nights. The flicker never seems to go away to my eyes. The blues are more tourquoise than blue to the eye, although the pix below show a real blue. The tint range is above average. There is enough color range for any eyes. But the detail in any video is gone...very gone. A function of the original set and whatever the Col-R-Tel does to the rest. The pix show the real image. Look close and you will see the mask is in focus and the video is what it is.

It suffers from having no delay line in the design compared to others like the Colordaptor which did. The color smear added to the luminance is offset to the right a bit. But the picture is quite viewable in 1956 terms. There is a trace of a scuff on the wheel where it rubbed on a pulley over time.

The Philco has been changed from the original 12LP4 to an aluminized 12KP4 for the added brightness. There is an aluminized version of the 12LP4 if you can find one. Dump the ion trap and all is well. The color filters drop the brightness about 60% or so, but the 12KP4 makes up for that. I can run it...in a darkened room...with no retrace lines and a very viewable picture. All fed by a VHS connected to my cable.

For a better description of how it works, I urge you to look at the website of James T. Hawes who has disscected it;

http://www.hawestv.com/mtv_color/colrtel_block.htm

The photos are from an Olympus 810 in "night scene" mode which is a very slow shutter speed and gives the full color view. There is some motion blurring to them. Someday when I have the time, I will compose photos of a test still image to show the individual color images and the resulting brightness of each filter that makes a full color image.

Dave A

Great pictures Dave!

There's almost something magic about the way these work, seeing color on a B&W tube, simply incredible! :banana:

Youa are right Dave A, the flicker NEVER goes away. My Col-R-Tel also looks very smeary and low resolution, though the color is good. It is almost hypnotic to watch it. Eric is right, people find it almost magical to watch in in operation if front of a B&W set.

Eric,

ETC (Experimental Television Center) is located in Owego, NY.

109 Fairfield Rd.
Newark Valley, NY 13811

From what I could fine out, ETC may have links with Binghamton University:

Cinema Department, Binghamton University, SW-203B
Binghamton, New York 13902-6000
607- 777-4998, Fax: 607- 777-4648

Also, Ralph Hocking is the director and can be emailed at :

[email protected]

or contacted through his web site directly at:

http://www.experimentaltvcenter.org/ralphdvd.html

Super great pix! To think all that color comes from ordinary P4 phosphor.

I second the amazement at the color you get from a P4 source. IIRC, the P4 formula changed over the years - by the time that B&W was being phased out in favor of color, it had settled on a sulfide formulation that was a mixture of a violet-blue component and a greenish-yellow component. It doesn't seem that would give a lot of red. If you look at a white picture area on such a P4 tube with a small microscope or powerful magnifier, you can see the the two colors in separate phosphor grains. It would be interesting to know what the 12KP4 screen looks like under magnification

Old tv nut may be on to something here. Col-R-Tel had to use some unknown tube to set the standard for the Wratten filters they chose for the production release. With all of the possible sets that this could have been hung on, what CRT...and phosphor...was the standard?

With my 12KP4 in there, the blues as I noted are distinctly turquoise...a greenish contamination possibly from the sulfides OTN describes. Reds are vivid and greens are a bit yellowish. I have no idea why my pix put the blue back to where it should be other than that it is the sensitivity of the CCD in the camera.

James Hawes website offers a clue to the green that does not include phosphor varieties;

"The station doesn't transmit the third chroma signal, G-Y. This is the chroma signal that eventually produces green. (and this is why all color sets use green as the non-adjustable starting point for adjustments. Note by Dave A.) Most TV sets recover G-Y by adding samples of the B-Y and R-Y signals. Because Col-R-Tel only processes one color at a time, it can't add two signals. Instead, like some conventional sets, Col-R-Tel generates a third subcarrier to recover G-Y. On vector diagrams, the G-Y vector appears at about 7:00. In vector terminology, that's -106 or so from the B-Y signal. Without the advantage of a resistive matrix, Col-R-Tel creates green by phase shifting negative R-Y. Negative R-Y (roughly greenish cyan) resides on the 270-degree axis. That's 6 o'clock. Col-R-Tel's 64-degree shift should produce a yellowish green. With the hue control, the viewer can adjust this color. Not bad."

So is this a product of the phosphor or the circuitry?

And we have yet to hear from Pete D on the obscure effects of chroma matrix settings vs. the CT-100 vs. modern cameras vs. old RCA TK-40 iconoscope color cameras vs. plasma phosphors.

I suspect these designers were just throwing darts and we are lucky that they work at all.

Dave A

I may soon have some more information to help solve this. I have color filter material that is very close to that used in the Col-R-Tel which I plan to put on the wheel in our CBS Color Converter. The field sequential system will remove the NTSC color encoding/decoding variable. I'll report the results when I get it done.

I'm curious about the excess red plastic sticking out the edge of the wheel. Was the wheel made by sticking colored plastic on a clear disc?

The plastic flap is there to cover the corner of a larger rectangular CRT. The Col-R-Tel included a 'size switch box' so it could be used with large CRT sets.

The box reduces the picture size to that of the wheel window, just slightly larger than a 12 inch round CRT face. The 'red' plastic flap has the same finish as the simulated mahogany wood pattern on the wheel housing.

The wheel is made of very high quality translucent plastic segments which
are held together with a good grade of clear adhesive tape and a staple near
the outer edge where the adjacent segments join.

I have seen 8 different Col-R-Tel systems over the last 45 years and I have never seen any in which this plastic material has faded, or fogged, nor has the clear plastic tape yellowed or it's adhesive dried out.

If anyone from the original Columbia City IN. Col-R-Tel Company is still living
or if the original records of manufacturing materials still exist, knowing what's in them would be agreat find.

Also, having a definitive list of the various models and a description of the differences between them would be good to have. I am aware of three different models at this point: 100-1, 100-2 and 101-2. I don't know if there was a 101-1.

I'm in the process of restoring my Col-R-Tel unit which I bought in 1960. It is mounted on a 12 inch Philco table top set.

I'm looking for a drive belt for it as well. A friend deals with a major supplier of 'O' Rings for the aircraft industry so it's probably a matter of time until I have
one.
Film @ Eleven

Cliff

Clif,

Is there a way to find the model number on the chassis. Mine is missing all of the original tape strips that had the control functions on it and I see nothing else.

Dave A

I have a real nice Col R Tel but no electronics. Anyone know of one available? Julian

I believe Ed (roundscreen) has the electronics but no wheel, and as I recall he was thinking of selling. Drop him a PM.

[QUOTE=Dave A]"Clif, Is there a way to find the model number on the chassis. Mine is missing all of the original tape strips that had the control functions on it and I see nothing else."

Hello, I haven't seen a chassis with the control functions on tape strips. The only two models I know of are the 100-1 and the 100-2. I have only seen 100-2s. You might have a 100-1, but I can't say for sure because I've never
physically seen one..

The only way I know to tell them apart is that the 100-1 has a variable capacitor C-20, and a fixed choke L-5 to trap out the 3.58 in the plate circuit of the 6BE6.

In the 100-2 they used a variable choke, L-7, and a fixed capacitor, C-32.

Also, on the Early Television Foundation website there is a Col-R-Tel owner's manual with a schematic for a 100-2. The schematic is labeled 101-2, but this might possibly be an error. http://www.earlytelevision.org/col-r-tel_manual.html

I hope this helps.
Regards,
Cliffr