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Mechanical Television

The place to chat about audio/video devices & software, computer hardware & software, and other electronic gadgets.
sfpcc
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Mechanical Television

Post by sfpcc » Wed Jul 26, 2017 12:22 pm

Has anyone out there heard or seen some called Mechanical Television. This is a brief description from its Wikipedia page.

"MECHANICAL TELEVISION or MECHANICAL SCAN TELEVISION is a television system that relies on a mechanical scanning device, such as a rotating disk with holes in it or a rotating mirror, to scan the scene and generate the video signal, and a similar mechanical device at the receiver to display the picture. This contrasts with modern television technology , which uses electronic scanning methods, for example electron beams in Cathode Ray Tube (CRT) televisions, and Liquid Crystal Displays (LCD) to create and display the picture."

I just saw this device on a couple of episodes of Modern Marvels, (an awesome show by the way) and though looked interesting, proved to be impractical to say the least, (the picture it produced kind of looked like scrambled ON TV) I'm sure there some languishing in a museum somewhere.



Arthur Mometer
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Re: Mechanical Television

Post by Arthur Mometer » Wed Jul 26, 2017 7:21 pm

Sounds like Philo T. Farnsworth's TV invention. Luckily, he didn't let Sarnoff and RCA depress him like Armstrong let him.


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RingtailedFox
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Re: Mechanical Television

Post by RingtailedFox » Thu Jul 27, 2017 1:29 am

yeah, instead of using a cathode ray tube and electron gun to fire electrons at a screen (something like 525x29.97fps = number of electrons fired), it was a rotating scan disk that would have an slot open as it rotated to manually scan it with a neon or selenium lamp glowing glowing and producing the video frames from the video signal recieved. the frame rates would be anywhere from 8 to 30 fps, but the detail was very limited (80 to maybe 240 scanlines, which would be VHS at *best*). those were the first ones used in the 1920s, 1930s and 1940s, but once the vastly superior CRT was perfected, it rapidly fell out of use.

the disk was an invention of Paul Nipkow (in 1884), and was used in the first television set made by John Logie baird in 1926.

They and Philo Farnsworth are all equal in my eyes in the question of "who invented television?". there was no single inventor.. just a group of unrelated and non-connected people making different contributions to the concept at differnt times, and improving on previous ones.


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organman95
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Re: Mechanical Television

Post by organman95 » Tue Aug 22, 2017 10:12 am

As to the improvements, I read somewhere that the Japanese were working on HDTV starting in 1969, and became available (although, Analog, not digital transmission) in the late '80s. Much perfected into the digital transmission it is today.

Though I still have my issues with it and prefer analog...at least you could still get a picture even if the signal was sketchy.



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RingtailedFox
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Re: Mechanical Television

Post by RingtailedFox » Mon Aug 28, 2017 5:31 pm

yeah, that would be MUSE (MUltiple Sub-nyquist Encoding). It was 1035i and provided what was basically HDTV but only on satellite dish service because the channels were 22 MHz wide. in the late 1980s, the FCC thought of trying to squeeze that down to fit into a 6 MHz channel, but the results were... well, bad. this was just before digital television was even thought of, though.


https://en.wikipedia.org/wiki/Multiple_ ... g_encoding


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SolarMax
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Re: Mechanical Television

Post by SolarMax » Mon Aug 28, 2017 10:35 pm

You reminded me that I saw MUSE demo'd at an NAB Show in the 80s. NHK had a special exhibit area set up. Other than that it was in widescreen aspect, a novelty at the time, and had lots and lots o' pixels, to me it was pretty unimpressive. Lousy temporal resolution, limited color space, etc. But, it WAS "high definition" and it was being transmitted direct from satellite to at least a few viewers in Japan.



k8jd
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Re: Mechanical Television

Post by k8jd » Fri Jan 19, 2018 5:24 pm

I have seen pictures of those rotating disc TV devices, I think they were experimenting with a fairly slow scan TV signal between 2 and 3 MHz back around the 1920-30s.



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SolarMax
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Re: Mechanical Television

Post by SolarMax » Fri Jan 19, 2018 8:24 pm

k8jd wrote:
Fri Jan 19, 2018 5:24 pm
I have seen pictures of those rotating disc TV devices, I think they were experimenting with a fairly slow scan TV signal between 2 and 3 MHz back around the 1920-30s.
The Early Television Museum in Hilliard OH, west of Columbus, has a number of mechanical color sets on display. I don' t know if any of them are set up to live display field sequential color pictures, though.
http://earlytelevision.org/cbs_color_system.html



organman95
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Re: Mechanical Television

Post by organman95 » Tue Feb 06, 2018 2:25 pm

Had no idea there were mechanical color sets!



jry
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Re: Mechanical Television

Post by jry » Fri Feb 09, 2018 2:43 pm

Yes, this is not like what Dr. Capehart was working on in the late 20s.



In The Bleachers
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Re: Mechanical Television

Post by In The Bleachers » Sun Feb 18, 2018 1:30 am

While perusing for something else, I come across this article about a gentleman that, I suppose you could say, is a TV hoarder.
Almost at the end of the article is a picture of a mechanical TV.

https://www.theverge.com/2018/2/6/16973 ... ng-vintage


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