VERY vintage television

[ppppenguin]

The idea of seeing at a distance has a history that dates back to at least the middle ages. Here are some thoughts from the 1890s. This was after Willoughby Smith had discovered the photo sensitivity of selenium and after Nipkow had proposed his scanning disc.

From "Independent Broadcasting" issue 10 published by the IBA in December 1976.

[Mike Watterson]

And fairy tales etc had scrying (distance viewing) in bowls of water and mirrors maybe from 10th C. Crystal balls are a later idea.

So people wanted to develop the technology because they had the idea. The Camera Obscura idea is very old and may have been used by some of the "Old Master" painters, though earlier was in China. Still photos needed the discovery of Nitric Acid (to make photo sensitive silver nitrate) which dates from 13th C, but electric batteries were discovered/invented by Volta in 1799, first still photographs in 1822, electrical telegraph 1830s (Morse type systems 1848-1865) though there was earlier optical telegraph. Cold cathode CRT in 1897, hot cathode in 1922 (but could have been done earlier).
Marconi Wireless was used during the Boer War, and could have been used with Nipkow's mechanical TV. But by 1905 it was realised that Wireless Remote viewing (Television) needed an electronic camera. Farnsworth's was a dead end because no per frame storage/integration.

In 1911, Boris Rosing and his student Vladimir Zworykin created a system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, "very crude images" over wires to the "Braun tube" (CRT). Later some Dutch people used CRTs with the mechanical "Baird" system, before Baird used a CRT. Radio Fax was also used after hours in the USA on MW. Wired fax was first demonstrated about 1851. About 1909 saw a matrix of selenium cells used as a very low resolution camera. Colour transmissions on mechanical TV were in Germany about 1924.

Zworykin's big breakthrough was that each part of the camera target integrated over the entire frame interval, not just at the instant of reading (Farnsworth).

Electricity and photography gave inventors and scientists the impetus to pursue the technological realisation of "seeing at a distance" in old fairy tales.
Long distance "ẅriting at a distance" preceded electricity with Chappe in 1792. By the time of the Napoleonic War the networks stretched thousand of miles in Europe. Fictionalised in Terry Prachett's Discworld as the Clacks.

So the ingredients of TV were:
1799: Batteries and start of Electrical Age.
Movie film (a big spur) in late 1890s as development from photography in 1822.
1897 CRT
Marconi commercialising Maxwell & Hertz for radio in 1890s
Hot cathode CRT 1922
Maxwell on need only for R G B (mid 1800s) for Colour TV.
Amplifying valves (Edison, DeForest, Fleming etc)
Zworykin's camera tube was the final bit of the puzzle. The 1951 Colour was inevitable.

By the 1970s there was experimentation with Digital TV encoding and lasers on fibre optics for communication.
Semiconductor research predates valves. 1948 simply needed pure enough materials!

[ppppenguin]

I was trying to go back to the era before TV. From fables of distance viewing up to the start of the TV age.

AA Campbell-Swinton deserves some credit too! His work in 1908 and 1911 look startlingly like electronic TV systems that were created in the 1930s. https://en.wikipedia.org/wiki/Alan_Archi...ll-Swinton

Don't forget Bain who invented a fax system in 1843, some decades before the phone was invented: https://en.wikipedia.org/wiki/Alexander_...le_machine 

Fax can be thought of as very slow television. Mertz and Gray's famous 1934 paper A Theory of Scanning and Its Relation to the Characteristics of the Transmitted Signal in Telephotography and Television makes no distinction. The maths is a bit heavy - I did understand it all at one time. https://archive.org/details/bstj13-3-464

[ppppenguin]

A bit later than my intended period but Heath Robinson is always a good thing: https://www.scienceandmediamuseum.org.uk...id=1&pid=2

Until today I hadn't realised that this carton was published in the very first issue of Television magazine in 1928. This was the magazine of the "Television Society" and was published by the Baird company to promote TV. The Television Society received a Royal Charter in 1961(need to check) and the Royal Television Society is still very active. I've been a member since 1975 though I'm not sure it's relevant for me any more.

[ppppenguin]

Just noticed that I've posted a broken link. It's a known forum problem that things break after an & in a link. I've put it in code so you just need to copy and paste.

Code:

https://www.scienceandmediamuseum.org.uk/objects-and-stories/radio-television-enthusiasts-early-broadcasting#&gid=1&pid=2

[Mike Watterson]

I was trying to go back to the era before TV. From fables of distance viewing up to the start of the TV age.

My main area of writing theses days is based on old fables.

I was agreeing that it was part of the inspiration when the Electrical Age started in 1799/1800.

[Mike Watterson]

Just noticed that I've posted a broken link. It's a known forum problem that things break after an & in a link. I've put it in code so you just need to copy and paste.

Code:

https://www.scienceandmediamuseum.org.uk/objects-and-stories/radio-television-enthusiasts-early-broadcasting#&gid=1&pid=2

And links in Viber chat also break if they have ( and ) in them which is common with wikipedia

Hmm, does link text help?

Yes, typing text, selecting it and click on insert link does bypass the bug and you can hover mouse and have preview on status bar (if enabled).

[Kalee20]

A bit later than my intended period but Heath Robinson is always a good thing: https://www.scienceandmediamuseum.org.uk...oadcasting#&gid=1&pid=2

I've seen that cartoon before... but it's always good for a smile!

The TV receivers are all projection TV too, how forward-looking is that?

And the top picture... that the signal has to go all round the globe (as per the diagram pinned to the wall), that introduces a 150msec delay, obviously not seen as a drawback!

[Nick]

Just noticed that I've posted a broken link. It's a known forum problem that things break after an & in a link. I've put it in code so you just need to copy and paste.

Code:

https://www.scienceandmediamuseum.org.uk/objects-and-stories/radio-television-enthusiasts-early-broadcasting#&gid=1&pid=2

Please use the BB code "url" for URLs that have odd characters in them. Actually, just always use "url", as in:

Code:

[url]https://www.scienceandmediamuseum.org.uk/objects-and-stories/radio-television-enthusiasts-early-broadcasting#&gid=1&pid=2[/url]

I refer you to Mark's note on this:

https://golbornevintageradio.co.uk/forum...#pid100058