At the end of last year I purchased a 1938 electric motor and mirror drum for the National Television Collection from a private collector. Generally speaking we don’t collect electronic parts; however this object is an exception for a number of reasons.
As I investigated its history further, I discovered that it had a fascinating background. For one thing, it was a part of the best television made in Britain prior to the Second World War.
What is a high speed scanner motor and how does it work?
Our line scanning motor and mirror is from a 1938 Scophony optical-mechanical projection television set.
In the 1930s, television picture tubes (cathode ray tubes) were mainly small and dim, and only suitable for viewing in low light levels.
To get a large bright picture, Scophony engineers developed a revolutionary projection system using a high intensity mercury vapour lamp.
This light was then modulated (controlled) by a Jeffree cell, and scanned across the screen by 2 mirror drums, a small high speed one like this to produce the line scan, and a large slow speed unit to produce the frame scan (12 mirrors rotating at 250rpm).
It actually consists of 2 motors running on the same shaft, a standard induction motor to bring the unit up to speed, and a phonic motor (in reality another synchronous motor, but designed to work with high frequencies) which was synchronised to the line pulses of the incoming signal.
The motors turned a 20-sided stainless steel mirror drum (visible at the top of the unit) at 30375 RPM to reproduce live 405 line pictures being broadcast by the BBC.
Sadly, none of the TV sets this motor is designed to fit exist today. The Scophony company no longer exists either.
Who were Scophony?
Scophony was one of the most highly original television manufacturers of the 1930s. Their innovative optical-mechanical television systems produced large screen high-definition pictures for both the home and cinema.
The company operated internationally – in Britain and Germany in the early 1930s, and then in Britain and America in the late 1930s.
The story began with a visit to Germany in 1929 to see television pioneer Dénes Von Mihály. The founder of Scophony, entrepreneur Solomon Sagall, had decided to begin his first venture into television by purchasing the British rights to the Telehor television system from Mihály, founding a company called British Telehor Ltd.
The following year, a small German company was formed and given the name Scophony, while a British subsidiary was established.1 By 1936, this was formed into a public company, Scophony Ltd with the British radio and television manufacturer, EK Cole (Ekco) acting as one of two major investors.
The company’s contributions to television’s technological history have certainly not received the attention they deserve, in part because the Television Committee formed in 1935 made its decisions before Scophony’s technologies had been fully developed, and because no complete Scophony television sets survive today either in museums or private collections.
The most complete Scophony television in existence can be seen here in Bradford, on public display in Experience TV.
How was the Scophony television scanner used?
This motor was designed to carry out the line scanning (as opposed to frame scanning) in what was praised as the “best and brightest” television set on show at the Radiolympia radio and television industry exhibition in 1938.
The magnificent Ekco-Scophony model ES104 home receiver boasted a picture 24″ wide by 20″ high. The screen could fold into the richly veneered cabinet when not in use.
The set cost the equivalent of about £12,000 today – which was about twice as expensive as the finest cathode-ray tube based home receivers. The ES104 had 39 valves and consumed about 1000 watts. Production numbers in 1938 would have been very small, probably in single digits. I have found no evidence to indicate that any ES104 sets were sold.
Where did our Scophony motor come from?
Amazingly our motor came with its original box, which is fairly intact and it still has its address label. The label reads that the motor was sent by van to a Mr EH Traub from a Mr G Wikkenhauser.
Having written an article3 concerning Ernest H Traub in 2009, I knew only too well who he was.
A lesser-known figure in the history of British television technology, Traub was a physicist who designed and introduced a novel type of mechanical mirror-drum-based television receiver in 1935 known as the Mihály-Traub scanner – again in collaboration with Dénes Von Mihály, the Hungarian television inventor and engineer based in Germany.
The sender, G Wikkenhauser, was Gustav Wikkenhauser – also Hungarian – and a mechanical and electrical engineer who worked at Scophony in the 1930s along with Walton, Sieger, Robinson and Lee. In his previous job in Germany, he had worked for Dénes Von Mihály’s company, Telehor Ltd. It was Wikkenhauser who built the two 30 line television receivers Mihály demonstrated at the 1928 Berlin Radio Exhibition.4
Although there is no date on the box, I suspect that Wikkenhauser sent this motor to Traub in 1938. It seems safe to assume that there was a friendly collaboration going on between Traub’s company, Associated TeleVision, and Scophony (via Wikkenhauser). They had a common colleague in Dénes Von Mihály.
Our Scophony motor could be unique
This motor could very well be the only one left. I’m pleased it will be safely preserved within the National Television Collection to compliment our other Scophony artefacts.
It was interesting to correspond with the collector who sold it to us, and discover where he had found it – 34 miles northwest of London as it turned out…
I found the unit on the local tip in Chesham, Bucks, in about 2002, and purchased it as scrap. It has since been seen at a couple of small displays, at Broadway Baptist Church in Chesham, and at Twyford Waterworks, in Twyford Hants, as well as a picture being on my webpage for some years. It did once make a brief appearance at the BVWS swap meet in Harpenden. As to where it hid in the intervening years, I have no idea, though all sorts of interesting bits used to turn up on Chesham tip!
Our other Scophony artefacts include a collection of documents, news clippings and photographs from the files of Scophony engineer Joshua Sieger. There is also an original Jeffree Cell, and a couple of examples of Scophony advertising literature – a fold-out black and white pamphlet and a colour poster.
Further reading and interesting links
- Singleton, T The Story of Scophony (London, Royal Television Society, 1988)
1 Burns, R W Television: an International History of the Formative Years (IET, 1988) p252
2 Singleton, T The Story of Scophony (London, Royal Television Society, 1988) p93
3 Baird, I L ‘The Mihály-Traub Scanner’, The Narrow Bandwidth Television Association (NBTVA) Newsletter, 2009
4 Singleton, T The Story of Scophony (London, Royal Television Society, 1988) p21