Should have called the article...
"The history of the idiot box..."
BBC TV, famed for such nation-capturing programmes as Playschool and Great British Bake Off, celebrated its 80th birthday last November. It did so in the same week that watching the country's then most popular TV programme, The Crown, required neither the BBC nor a TV set. Just a Netflix account and a connected mobe. With the …
>Uh, I wonder how he planned to transmit it? HDTV did not really become practical until sufficiently effective digital compression was available.
Curiously enough, Baird wasn't working with digital video! And even if he was, each pixel would require very few bits because of the narrow colour gamut the system used. Telechrome didn't render blues or greens very well, but produced acceptable pink skin tones.
The "enhanced" version involved shooting on film that was developed in real time as it came out of the camera and then using a telecine device to produce the video signal. Given that this meant the camera had to be in a fixed position, attached to the chemical baths. and that those baths had a tendency to leak causing an amusing variety of safety hazards, it is amazing it didn't get laughed out at the planning stage.
He really should have stuck to the socks and the soap.
Film was never processed in space, just way to tricky to do that in zero gravity. Early satellite however did take pictures on film which was then returned to earth using a variety of mechanisms. Some of which included plucking it out the sky as it descended on parachute to avoid it falling into enemy hands.
>Film was never processed in space, just way to tricky to do that in zero gravity.
Film was developed in space, on the Luna 3 probe which provided humans with their first ever images of the moon's far side:
After photography was complete, the film was moved to an on-board processor where it was developed, fixed, and dried. Commands from the Earth were then given to move the film into a flying spot scanner where a spot produced by a cathode ray tube was projected through the film onto a photoelectric multiplier. The spot was scanned across the film and the photomultiplier converted the intensity of the light passing through the film into an electric signal which was transmitted to the Earth (via frequency-modulated analog video, similar to a facsimile).
Interestingly, the temperature resistant and rad-hardened film used by the Soviets for this mission was salvaged from USA spy balloons.
So jabuzz, never say never! :)
EDIT: a good link here: https://www.damninteresting.com/faxes-from-the-far-side/
"it is amazing it didn't get laughed out at the planning stage."
Hindsight is great isn't it.
Now, try putting yourself back in time when none of the modern technologies we take for granted existed, and consider his solution as a brand new thing.
The cathode-ray tube, when it was invented, must have been quite something - but before someone came up with that idea and made it work ... Baird's original invention must have looked at least plausable and worth trying to improve.
Cathode Ray tube was Victorian, yet Dutch, not Baird was first to use it for display of Baird mechanically scanned TV.
The real problem, as Philo Farnsworth found, was the camera tube. Farnsworth's was very poor sensitivity because it didn't store charge. Baird bought some, but the film camera was better. The RCA / EMI system developed by Vladimir Zworykin.
1933 RCA Electronic camera (HD if on 9" display!)
It was based on his design started at Westinghouse Electric in 1923
Baird was rubbish, chasing a dead end.
"In 1907, Russian scientist Boris Rosing used a CRT in the receiving end of an experimental video signal to form a picture. He managed to display simple geometric shapes onto the screen, which marked the first time that CRT technology was used for what is now known as television. In 1897, J. J. Thomson, an English physicist, in his three famous experiments was able to deflect cathode rays, a fundamental function of the modern Cathode Ray Tube (CRT). The earliest version of the CRT was invented by the German physicist Karl Ferdinand Braun in 1897 and is also known as the Braun tube"
"In 1926, Hungarian engineer Kálmán Tihanyi designed a television system utilizing fully electronic scanning and display elements and employing the principle of "charge storage" within the scanning (or "camera") tube"
Hindsight is great isn't it
It was clear at the time. Baird's wet film system was a response to the CRT. not a precursor to it. He
rushed to develop it because EMI Marconi were obviously going to beat his original mechanical system (which had a whole raft of other drawbacks too) hands down in the BBC trials. By that stage he was just desperately trying to protect his investment which meant finding any possible means to try to delay or undermine the clearly superior technology.
Mindsets recently started selling Televisor kits for forty quid, so you can build a working Baird television and see just how terrible it was.
I wonder where the British equivalent The IET (nee The IEE) was among all these celebrations of British invention?* They have some claim of interest in the early days of telly as their HQ (Savoy Place, London, on the Embankment) was the original BBC HQ before Auntie moved to Portland Place. I seem to recall on a visit many years ago they had a large picture of Lord Reith locking the doors of Savoy Place for the last time.
*Genuine question - I see no mention of them in the article.
Whilst it's true that Baird was the first to publicly demonstrate television, like Edison he wasn't an inventor so much as a refiner of ideas and a shameless self-promoter. Electromechanical systems were a technological dead end and that was widely realised within 2 years of Baird's demonstrations.
There were a number of people around the world working on systems using Nipkow discs and they all had the same problems with synchronisation. The BBC system was one of the widest trials and viewers seldom got more than a few minutes of viewable pictures at a time.
The father of Television as we know it is Philo Farnsworth and it was his work which made people realise that electromechanical systems were impractical. The breakthrough was his Image Dissector in 1926 and elimination of all mechanical components (CRTs were already well known) which was closely followed by a bunch of related camera and electronic developments that mostly bypassed the UK thanks to continued concentration on trying to make electromechanical systems work.
(Does concentrating on pushing dead-end technologies in the face of demonstrably better ones sound familiar?)
Philo Farnsworth's camera was electronic and also a dead end. Nor was it anything like an original concept or the first.
It's just the USA sees him in same light as UK sees Baird, a plucky underdog fighting the big corporation. Actually EMI was originally HMV, the UK branch of the Victor Talking Machine Co., bought by RCA, that had once had Marconi as a founder.
So EMI / RCA camera co-operation and also Marconi transmitters in UK is no surprise.
Double the resolution of a Farnsworth camera and the sensitivity is half. It was at the start 100s of times less sensitive than the Iconscope (Early RCA & EMI camera). The RCA/EMI system sensitivity was only much affected by frame rate as it stores the charge on the image between scans.
Philo Farnsworth's camera was doomed to never be usable at feasible lighting levels and even 220 lines (which Baird tried it at).
There's some confusion in the article about line resolutions. Baird's original mechanical system was 30 line, but by the time of the Baird mechanical versus EMI electronic runoff the Baird system was 240 line, and EMI 405. The BBC started in 1936 with the EMI 405-line system, not a "240 line HD" service.
French 819-line broadcasts, arguably a true HD service, started in 1948 but it didn't last and they settled on 625-line like the rest of Europe.
He didn't invent modern TV. He started with a 22 line mechanical system, based on Victorian tech. The last version (using CRT display and film based cameras) was 220 lines.
RCA & EMI developed modern TV based on a 1905 idea. USA was 440 (later 525) and UK was 405. Operational from 1935.
On a 9" screen (typical) it was indeed HD compared to 1920 x 1080 on a 42" screen today.
WWII saw higher resolution used for Nazi rocket range CCTV.
1948 saw 625 line in Europe.
Baird was a showman and not even a real engineer. Eventually the Baird company paid him to sit at home. The film based near real time camera with built in processing and scanning was clever and used in early satellites as electronic cameras were too poor. The film processed on the satellite could be high resolution and the scanning of it could be sent back slower than real time per frame, as it was really still photography.
Visible and system lines are different.
405 approx 378
525 is 480 (hence VGA is progressive version of NTSC)
625 is 576
1125 can result as 1080. My Analogue CRT actually is 1125 lines to do 1920 x 1080 HD via VGA connector.
I think I mentioned 220, when actually last Baird was 240, but I don't know how many visible lines.
The vertical TV scanfrequency is derived by dividing the horizontal scanfrequency by 405= 3x3x3x3x5, 525= 3x5x5x7, 625= 5x5x5x5 resp. 1125= 3x3x5x5x5. Reason was that frequency dividers using valves (tubes) could only handle small odd numbers (R.A. Alexander, The Life and Works of Alan Dower Blumlein, the inventor of stereo, Ch. 5 EMI and the Television Commission) in contrast to transistor-dividers (TTL) which which prefer division by powers of 2.
BTW, the first fully electronic television principle was put forward by Alan Archibald Campbell-Swindon during is address to the Röntgen Society in 1911.
"Reason was that frequency dividers using valves (tubes) could only handle small odd numbers"
There was also a requirement to have the frame rate match mains frequency both to avoid visible flicker effects and because it was a stable frequency that the scan oscillators could lock on to, making getting a stable picture that much easier in the days of temperamental valve TVs. It was bad enough with monochrome sets, the few valve-based colour sets sold were virtually impossible to keep stable and thankfully weren't around for very long before transistorised sets ate their lunch - and even then, the build quality of most sets was appalling.
In my early days as an apprentice in the 1980s I saw many 1960s and 70s sets with unsoldered joints, etc - making it clear why the things required endless "percussive maintenance". Thankfully there were only about a dozen common chassis in the 1970s and endless cabinet variations around them, so once you had a database of typical faults they were easyish to fix - but the most common problem other than dodgy joints finally failing was nicotine buildup on High voltage components. (disgusting to clean!)
The fun part is even with "standards" you can have incompatible variants and I'm not talking about the 5.0/5.5/6.0MHz audio subcarrier offset (Pal B,G/I/D,K). Both CCIR (625/50) and NTSC(525/60) horizontal and vertical sync pulses were both inverted in various countries (PAL D/K) to try and keep people from watching TV from neighbouring countries (the russians and the french were particularly bad offenders with not only the odd PAL setups but also SECAM (known in the trade as "something essentially contrary to the American Method") and polarity tweaks on that).
On top of that, NTSC and PAL encoding were also swapped around in various countries, resulting in 525/60 3.58MHz PAL in come countries and 625/50 4.43MHz NTSC in others (PAL-M and NTSC-N - both widespread in south america).
For all the chestthumping, PAL was relatively easy to come up with as it's a simple extension on NSTC that makes it much more resistant to colour shifts from multipath reception (ie: Ghosting) and reduces transmitter power consumption at the same time. The 3.58 and 4.43 MHz subcarriers are artifacts of the scanning frequency, not the encoding system.
Marconi wagon mounted Wireless sets were sent to British forces for Boer War. They could in theory have sent radio fax (wired fax dates from 1851!) or 22 line Nipkow disk (like Baird TV) TV from South Africa to London. It would have needed some repeating stations, receiving on to recordable 78s (which may have existed) or Edison cylinders and retransmitted.
Some home recordings of Baird TV exist on 78s intended for home recording of Radio. The Baird tests started with AM radio after hours. Some of the USA AM stations had radio fax transmission in early 1930s after hours as well as the USA version of Baird TV.
Nothing unique or innovative about early Baird systems. The later ones overlapped superior RCA & EMI electronic TV.
In the UK the Post Office had a monopoly on "telegraphy". Radio when it came along was dubbed "wireless telegraphy", and thus part of the monopoly. That's how the BBC came into being, and how television became such a bureaucratic mess in its early years.
Could you image Tesla doing what he did in the UK? Marconi would have been arrested as soon as he connected his aerial to his transmitter.
Marconi got his first big breaks with the UK P.O. That started his career.*
The P.O. was surprised at his good English, but his mother was posh Anglo-Irish and had encouraged him to experiment on their Italian estate.
One of his wives was Irish too.
Marconi had more difficulty in USA, eventually being forced to sell his holding in what became famous RCA.
[* There is even an accurate Ladybird book on the subject]
A Crown-chartered corporation isn't state owned. It's /created/ by the state, but it's owned by itself and cannot be bought.
Though, as with all and any property in the UK, Parliament Is Sovereign and Parliament can appropriate ownership of all and any property to the state with or without compensation and can disburse it at its will. Read up on how the government in the 1980s tried to declare that it should receive the proceeds of TSB converting itself into a commercial company and selling shares in itself.
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