Hello folks, this new section of AK forum is devoted to mechanical televisions, and this thread will be the spot for "bragin' pictures". Of course you are welcome to start subject specific threads as well. Please bear with me as I am new to moderating these things!
Thanks!
Marlin Mackley

The color system that was championed by CBS in the early 50's and that is still used in some industrial and scientific applications because it can use a single B&W camera and phase distortion in the broadcast link does not distort the color reproduction (NASA uses this type of camera on its spacecraft probes) was employed by Eidophor to produce color in its single light-valve projectors. I have several of their 1970's vintage model 5181 that came out of a ship's wheelhouse simulator at the Merchant Marine Academy, Long Island, NY. These projectors use a rotating dichroic filter wheel in the intense light path from the xenon arc lamp on its way to the light valve. Solid state electronics regulate the speed and phase of this wheel and also control video gain and pedestal for each color field. I have had one of my projectors working in the 441 line / 180 field video format on the special color bar and test pattern generator which I acquired with the lot purchase of these machines.

Here is a picture of the ship's bridge I spoke of in the simulator with the computer generated "CBS" color visible through the wheel house windows.

Does this one count?

:lmao:

...and its fully programmable too!

See Marlin, this is the kind of stuff you will have to learn to tolerate as a good moderator. ;)

I remember those old ship radars with the round crt's. We had one of those on a T2 tanker I used to work on. They don't do near as much as today's radars, but seemed to last forever.

Dear: House de Kris
I think the resolution is too high, ain't it??:uzi:
Charlie: I believe those early radar crts used a mechanical scan in so far as they rotated the single direction yoke around the neck.
Rob: Hey I am easy to get along with!

This thread disappeared a couple of years ago, but is still linked to threads I have started, so I posted this just to see what happens.
Marlin

This thread disappeared a couple of years ago, but is still linked to threads I have started, so I posted this just to see what happens.
Marlin

I have two .PDFs on a piece on the Field Sequential Color Eidephor System CBS and Twentieth Century Fox developed in the early 1950s for theater television.

Don't know how to add it to this post since there is no 'attach' button to click on...
Can somebody tell me how to do it? Each one is about 860K.
Regards,
Cliff

About 10 years ago I wanted to build a color wheel TV. I had pieces of an old Col-R-Tel unit but not enough to make a system. I also wanted to make something that would look really good with lots of resolution and less flicker than the Col-R-Tel, so I have worked on this project off and on, revising and improving it to the point where it now runs 640 X 480 @ 90 progressive frames per second [30 RBG color pictures per second] and has subjectively about the same amount of flicker as a PAL TV set. It is still a work in progress and I would really like to increase the vertical rate to 120 or 144 or maybe 180 frames per second. This gets difficult, but not for the reasons you might first think. It's not the wheel or the motor or the video, it's the monitor.

I can't find a nine inch monitor that will operate at this high a display rate.

I can spin the wheel fast enough and make a video signal that fast but can't find a 9 inch CRT monitor that will diosplay it.

I will probably have to build another set with a larger PC color monitor [with it's RGB inputs all tied together to make a monochrome picture] but that also means building a large 36 inch diameter color wheel for it as well. That will be more fun anyway.

Attached is a photo of the present 9 inch wheel set from the top rear.

Cliff

[QUOTE=cbenham]I have two .PDFs on a piece on the Field Sequential Color Eidephor System CBS and Twentieth Century Fox developed in the early 1950s for theater television.

Here's the first one...

Here's page 2 of the color eidephor piece

Page 2?

When I think mechanical TV, I think of, like, Western Visionettes.

That fits better with the premise of the Early Black & White forum...well...black & dull orange.

Cliff, thanks for the Ediphor article. Here'e an interesting link that is similar to your PDF but has more details and some intereseting pictures of the Ediphor Theatre Television System.

http://www.experimentaltvcenter.org/history/tools/ttool.php3?id=16&page=1

Gretag manufactured a modern version HDTV capable based on the color dot sequential system replacing the original CBS field sequential method.

Another system that owes much to Ediphor was the GE Talaria system

http://www.hi-def.com/12K.html

Tom

When I think mechanical TV, I think of, like, Western Visionettes.

That fits better with the premise of the Early Black & White forum...well...black & dull orange.

Agreed. Mechanical TV once had its own Forum division with its own threads, which I moderated, but disappeared a couple years ago, presumably from lack of activity. The other day I found I could access this thread of taht Forum through my personal AK account page and tried a post to see what happened, and where it showed up.
Marlin

[QUOTE=David Roper]When I think mechanical TV, I think of, like, Western Visionettes. That fits better with the premise of the Early Black & White forum...well...black & dull orange.

I watched a program on a Western visionette a friend in CT restored. 45 scan lines, three 15 line fields. I was allowed to 'take over the helm' and steer the wheel.

I'm getting more interested in mechanical TV and may try to build one from the parts made by Peter Yancer. I watched TV on his 'Mirror Screw' receivers he showed at the Early Television Foundation Convention last April. Just amazing stuff.

"Gretag manufactured a modern version HDTV capable based on the color dot sequential system replacing the original CBS field sequential method. Another system that owes much to Ediphor was the GE Talaria system." Tom[/QUOTE]

I got to play with a Talaria about 1979, and a year or so later saw a pair of
Eidephors set up at the NAB convention to produce an 8:3 image about 40 feet wide. They needed Cinerama 'giggolos' to blur the seam of the pictures together.

Projectors have come a long way since the live J. L. Baird mechanical color TV demonstration at the Domintion theater, London, to a surprised audience of 3000 on Feb. 4, 1938.

I wonder what that system might have sounded like when it was operating?

Here are pix of my Western Visionette and my Echophone 41. Echophone was owned by Western Television at the time the 41 was made [1933]

[QUOTE=David Roper]
I'm getting more interested in mechanical TV and may try to build one from the parts made by Peter Yancer. I watched TV on his 'Mirror Screw' receivers he showed at the Early Television Foundation Convention last April. Just amazing stuff.

I can recommend it highly. It's a fun project, and the scanning discs Peter supplies are excellent, giving great pictures once you add your own motor and electronics. You can get an inexpensive video source from a CD player and the CDs offered by the narrow band TV association. And you can later consider getting a scan converter (more expensive) to display NTSC sources; or build a live camera (more difficult than the receiver, however).

Here are pix of my Western Visionette and my Echophone 41. Echophone was owned by Western Television at the time the 41 was made [1933]
Wow! A couple of great sets you have there! :thmbsp: Are they complete and operational? There cant be many of those Echophones around!

The Visionette is complete and working using Darryl Houck's converter that converts NTSC to the 45 line triple interlace format. I haven't started on the Echophone yet but hope to get it working,too.

Wow! A couple of great sets you have there! :thmbsp: Are they complete and operational? There cant be many of those Echophones around!

Here is another Western Model 41 that is owned by my father-inlaw. I was told that the one my father inlaw has was the fifth one known of according to Steve McVoy. Not as good as shape as Pronostalgia's but I hope to restore it someday.

Fascinating!

Yes, but also saddening in that "pronostalgia" is the AK handle of the late Dave Johnson. I tend to doubt he ever got to restore the Echophone.

About 10 years ago I wanted to build a color wheel TV. I had pieces of an old Col-R-Tel unit but not enough to make a system. I also wanted to make something that would look really good with lots of resolution and less flicker than the Col-R-Tel, so I have worked on this project off and on, revising and improving it to the point where it now runs 640 X 480 @ 90 progressive frames per second [30 RBG color pictures per second] and has subjectively about the same amount of flicker as a PAL TV set. It is still a work in progress and I would really like to increase the vertical rate to 120 or 144 or maybe 180 frames per second. This gets difficult, but not for the reasons you might first think. It's not the wheel or the motor or the video, it's the monitor.

I can't find a nine inch monitor that will operate at this high a display rate.

I can spin the wheel fast enough and make a video signal that fast but can't find a 9 inch CRT monitor that will diosplay it.

I will probably have to build another set with a larger PC color monitor [with it's RGB inputs all tied together to make a monochrome picture] but that also means building a large 36 inch diameter color wheel for it as well. That will be more fun anyway.

Attached is a photo of the present 9 inch wheel set from the top rear.

Cliff


Beautiful work!:tresbon:
Have you any shots from your tv?
Flicker from a PAL TV is good for me, pheraps because i don't know the 60 Hz flicker.
Do you know well PAL's performances?
And finally, in your opinion, a wheel-based tv set can display a decent PAL picture?
Thank you.

As I was doing my usual searches for TVs on the internet I came across this EchoPhone Model 41 which sold at auction in 2009 for $3000

http://www.iowa-antique-radio-club.com/IARCHSSummer09.pdf

That would be a sweet find!