Commercial Television is 70 years old today.

[Penthode]

July 1, 1941 - The first commercial TV licenses were issued to WCBW (later WCBS-TV) and WNBT (later WNBC-TV), New York City. (On September 1, 1941, KYW-TV, Philadelphia became the third licensed station for commercial operation.)

http://www.paleycenter.org/b-simon-t...razy-day-of-tv

[aaaxada8CD7]

Incredible,then who invented the first TV?In developing countries,many people first see TV in the 80s last century

[edison64]

Philo t Farnsworth. Most of his ideas were stoked or pirated by RCA. Only many years after his death did the courts rule in his favour. There were many others who improved his ideas. But without his early experiments . Do a wiki search. Or better yet check out the numerous books about him and his life. Most people think of him as having the same hairbrained ideas as Tesla's.

[Dasun]

My first post here - a lurker with an interest in old electronics - but electronic TV broadcasting got underway in November 1936 in London England (not commercial but electronic TV broadcasting is 75 years old this year and Schoenburgs(sic?) EMI team (Blumlien invented the video waveform as we know it) did an amazing job at the time with the 445 line system that lasted until the mid-1980's). Farnsworth's image disector tube was not really practical - due to the lack of a photo-multiplier - although it found industrial uses later and the EMI team used a derivative of the RCA's Iconoscope called the EMItron. TV had many fathers (can't remember the Hungarian dude who came up with interlacing but EMI used that) which probably explains why it is such a mongrel! I will return to lurking after that dump, please correct any misconceptions I might have!

[tubesrule]

Farnsworth was one of many people who devised and held key patents in early television development. To say he is solely responsible diminishes the contributions of people like Dr. Ray Kell, Kálmán Tihanyi, Vladimir Zwoykin, Alan Blumlein, etc.

While Farnsworth is generally credited with demonstrating the first all electronic television, his Image Dissector camera tube proved to be a dead end for normal television use, while Tihanyi's storage iconoscope (patented in 1926 prior to Farnsworth) proved to be the right solution. Farnsworth's Oscillite display tube also proved to be unworkable and all crt's to this day use Zworykin's kinescope design of 1929.

All scientific endeavor is built on the back of prior knowledge in the art. Without Paul Nipkow, would Farnsworth or anyone else have thought of scanning? Of course they would have, Nipkow just got there first. Which brings up one of the biggest myths about Farnsworth and the story of him plowing a field and noticing the plowed rows. Upon viewing this he is said to have had the eureka moment that he could scan an image like this. Now it is known that he was a voracious reader of scientific magazines and scanning was already know at the time (Nipkow 1884) so this is just one of those larger than life stories that keeps getting repeated.

There are many very poor web sites on the internet on this subject. Unfortunately personal opinion's and prejudices are usually presented as fact on these sites which leads to much misinformation. To wrap this invention up in a nice, tidy little package makes for great story telling, but does not represent the historical facts. If you dig enough, you can discover all the great people that contributed to developing television to what it is today, including but not limited to Farnsworth.

Darryl

[kx250rider]

The concept was first demonstrated by Bakewell in England in 1847, but that was more of a fax machine than a TV (it was called "still television"). In 1884, Paul Nipkow demonstrated the scanning disk TV system, and John L. Baird basically made it all work. There were many many other inventors involved, and no single man can be credited with the invention of TV, IMHO. CERTAINLY NOT the abominable David Sarnoff and his clan of mobsters known as RCA.

Charles

[W.B.]

Not on this very day in 1941, but by the end of the year (if not a few weeks or months into commercial TV in the U.S.), an early version of the "NBC Test Pattern" below was first inaugurated.

As on this recreation, this was how it looked after the 1947 mods in which the wedge calibration dots were altered in their positions. The first variant of this TP can be found on this page.

(On the Paley Center's page, they used another repro of the basic TP design.)

[wa2ise]

Back in 1941 TV was 441 lines 30 frames sec/60 fields sec/ interlaced, with AM sound. Which must have sounded awful. Then WW2 happened. Japan, which according to the history I was taught in school did not exist before Dec 1941, attacked Pearl Harbour and with Germany WW2 was on, and no consumer electronics was made for a few years. Afterwards the FCC decided to make it 525 lines, and make sound FM, to Sarnoff's great joy...

[Penthode]

Actually, the system that the FCC approved for commercial broadcast in May 1941 and officially launched on July 1 1941 is what we have today (or at least until recently). Namely 525 lines and FM sound.

The first NTSC in 1940 saw to that. 441 was moribund in 1940.

[Sandy G]

Originally Posted by kx250rider

The concept was first demonstrated by Bakewell in England in 1847, but that was more of a fax machine than a TV (it was called "still television"). In 1884, Paul Nipkow demonstrated the scanning disk TV system, and John L. Baird basically made it all work. There were many many other inventors involved, and no single man can be credited with the invention of TV, IMHO. CERTAINLY NOT the abominable David Sarnoff and his clan of mobsters known as RCA.

Charles

Don't be dissin' The General, Charles ! (grin)

[ppppenguin]

Originally Posted by tubesrule

Without Paul Nipkow, would Farnsworth or anyone else have thought of scanning? Of course they would have, Nipkow just got there first.

Picking up on kx250rider's post. Nipkow certainly wasn't the first to have the idea of scanning an image for transmission. Bain devised an experimental fax in the 1840s: http://en.wikipedia.org/wiki/Alexand...simile_machine According to Burns (Television, an international history of the formative years) Bain took out a patent in 1843 and demonstrated the device in 1848.

I have no idea if anyone had the scanning idea before him. Nor do I know if Nipkow was aware of Bain's work.

As for interlace, Paul Marshall first brought Ulises Sanabria to my attention. This page claims he used interlace in 1926: http://www.televisionexperimenters.com/sanabria.html Not sure when baird first used interlace which he called intercalation.

A little OT for this thread but a reminder that November this year sees the 75th anniversary of BBC 405 line television. The British vintage Wireless Society will be marking the anniversary with an event at Ally Pally: http://www.vintage-radio.net/forum/s...ad.php?t=69409

[tubesrule]

Originally Posted by ppppenguin

As for interlace, Paul Marshall first brought Ulises Sanabria to my attention. This page claims he used interlace in 1926: http://www.televisionexperimenters.com/sanabria.html Not sure when baird first used interlace which he called intercalation.

Jeff,
This is true. Sanabria used a triple interlace system on his 45 line mechanical televisions, the most famous being the "Western". I have never been able to determine why he chose triple interlace versus dual. I am not aware of any other commercially available mechanical television that employed interlace.

Darryl

[MelodyMaster]

Originally Posted by wa2ise

Back in 1941 TV was 441 lines 30 frames sec/60 fields sec/ interlaced, with AM sound. Which must have sounded awful. Then WW2 happened. Japan, which according to the history I was taught in school did not exist before Dec 1941, attacked Pearl Harbour and with Germany WW2 was on, and no consumer electronics was made for a few years. Afterwards the FCC decided to make it 525 lines, and make sound FM, to Sarnoff's great joy...

The British 405 line standard, in use until the 80's, used AM sound which wasn't "awful." I still have quite a few audio recordings of 405 I'd made, from the late 50s to 1963, for a current reference. And of course early missing doctor Whos use off-air 405 line sound for CD compilations...

[cbenham]

Originally Posted by tubesrule

Jeff,
This is true. Sanabria used a triple interlace system on his 45 line mechanical televisions, the most famous being the "Western". I have never been able to determine why he chose triple interlace versus dual. I am not aware of any other commercially available mechanical television that employed interlace.

Darryl

Could he have been thinking ahead to color?
Cliff

[old_tv_nut]

Originally Posted by cbenham

Could he have been thinking ahead to color?
Cliff

I don't think triple interlace is heading in a good direction for color. Higher order interlace reduces bandwidth and large area flicker for a given resolution, but the problem is that line crawl/flicker becomes worse. Going to color either line sequential or field sequential makes these problems nearly three times worse.