A D V E N T U R E S   in   C Y B E R S O U N D

Dead Media : Early / Mechanical Television Systems by Richard Kadrey - edited by Russell Naughton


Introduction

According to Business Week in 1931, television broadcasters admitted...

"that interest in their efforts is confined almost entirely to the experimenter = the young man of mechanical bent whose principal (sic) interest is in how television works rather than in the quality of images received."

William Boddy, 1991

Fred Hammond, VE3HC, is a veteran Radio Ham who has been on the air since 1929. During the early 1930's, he was one of a handful of radio experimenters in Canada to become interested in mechanical television, building his own mechanical kit vision receiver. As an active Radio Ham, he was able to audibly monitor the various mechanical television signals.

Always a sensation, television was hardly an overnight success. In 1926, New York Times radio editor Orrin Dunlap called the new medium "an inventor's will-o'- the-wisp." A year earlier, a Scot, John Logie Baird, and an American, Charles Francis Jenkins, generated the first live pictures by pairing (or synchronizing) primitive mechanical scanning discs at transmitter and receiver ends. These demonstrations, soon conducted at department stores, trade fairs, and before invited audiences of scientists and government officials, attracted the curiosity of press and public.

dm_baird_theory.gif

The Baird/Jenkins System

Mechanical TV: How it works

The scanning and reproducing discs are similar. Both are mounted on driving motors, and each is punched with a spiral of small holes along the outer edge. The number of holes matches the number of lines of picture definition.

At the transmitter in this mechanical system, the studio is in total darkness. A light emanates from a lamp behind the disc and, projected through the holes set in the spiral on the outer edge, scans the features of the subject's face. The photocell converts these variations in the reflected light into the electric impulses, which, once amplified, can be transmitted by radio waves.

At the receiver, the signal is converted into a sequence of bright flashes by the neon tube. The reproducing disc rotates rapidly in front of this tube, and converts each flash of the lamp into a small element of the image. The rapid speed of the disc makes "persistence of vision" possible for the looker-in.

"Persistence of vision" means that the brain retains an image for one tenth of a second after it is perceived by the eye. The rapid repetition of moving images (in film or television) tricks the brain into perceiving continuous images.

Especially interested were some of the quarter- million amateur "wireless" operators, whose numbers grew during the early 1920s, when "radio mania" swept North America. These hobbyists were among the original producers and consumers of both radio and television. In 1928, Jenkins began irregular broadcasts of the crude silhouettes he called radiomovies. He described the thrill for his amateur audience as they "fished" for his signals on homebuilt contraptions:

"thousands of amateurs fascinatingly watch the pantomime picture in their receiver sets as dainty little Jans Marie performs tricks with her bouncing ball, Miss Constance hangs up her doll wash in a drying wind, and diminutive Jacqueline does athletic dances with her clever partner, Master Fremont."

At its inception, radio "listening-in" was an active, mainly male pastime, requiring technical know-how, and constant adjustments to the set. "Lookers-in" to early mechanical television patiently fished for signals. Sometimes they caught tiny, indistinct images. A separate radio set could be used to tune in sound with the picture.

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Baird Televisor

Radio entered most households only after it was domesticated. This meant that it came to resemble furniture instead of a gadget, became easier to operate, and could be enjoyed by more than one person at a time. Television followed a similar route into the home, but its complex and expensive assemblage dictated a lengthier experimental period before costs came down, and before the invention of larger screens and clearer pictures could domesticate "seeing at a distance."

Despite these early limitations, the pioneers of crude mechanical television demonstrated basic principles of picture scanning and synchronization of transmission and reception. They also glimpsed the medium's potential for storytelling. In 1928, the first live drama broadcast, a three-camera production called "The Queen's Messenger," was received on a General Electric Octagon set in Schenectady, New York. In 1931, the Radio Corporation of America (RCA) broadcast experimental signals from the Empire State Building, featuring a familiar cartoon character, Felix the Cat. The first TV star was born.

FELIX_THE_CAT.GIF

Felix The Cat

By 1935, mechanical television had reached a dead end in North America. Image resolution remained low, at best reaching 120 lines of picture definition. Transmission and reception standards were nonexistent. Available programming was unpredictably scheduled. Lacking an audience, advertisers were reluctant to purchase commercial time.


The Pioneers


Paul Nipkow

One of the earliest proposals for a mechanical television system was put forward by German researcher Paul Nipkow in 1883. When he developed patent No. 30,105, he was an unknown twenty-three-year-old student living in Berlin. It proved to be the basis for most early television schemes in the world, although he never built the apparatus.

In Nipkow's patent, which he called an electric telescope, a disc was punched with holes in a spiral near the outer edge. When the disc revolved, each hole vertically scanned a line of the image, allowing variations in light to reach a selenium cell. As one hole swept over a segment of the picture, the next in sequence tackled the portion next to it, until the complete subject had been scanned. The selenium cell transferred the light variations to an electronic signal. Pictures were reconstituted at the receiver by a similar disc which was synchronized with the transmitter.

Charles Francis Jenkins

One of the better known experimenters with mechanical television was Charles Francis Jenkins, a prolific American inventor. In May 1920, at the Toronto meeting of the Society of Motion Picture Engineers, Jenkins introduced his prismatic rings as a device to replace the shutter on a film projector. This invention laid the foundation for his first radiovision broadcast. He claimed to have transmitted the earliest moving silhouette images on June 14, 1923, but his first public demonstration of these did not take place until June of 1925.

Jenkins Laboratories constructed a radiovision transmitter, W3XK, in Washington D.C. The short-wave station began transmitting radiomovies across the Eastern U.S. on a regular basis by July 2, 1928. Jenkins wrote in 1929:

"This gave the amateur action-pictures to 'fish' for; and during August following a hundred or more had finished their receivers and were dependably getting our broadcast pictures, and reporting thereon, to our great help."

It was in this way that Jenkins actively promoted enthusiasm and experimentation in the short-wave radio community, and the U.S. experienced its first television boom, with an estimated 20,000 lookers-in.

John Logie Baird

John Logie Baird, a Scottish engineer and entrepreneur, achieved his first transmissions of simple face shapes in 1924 using mechanical television. On March 25, 1925, Baird held his first public demonstration of television at the London department store Selfridges on Oxford Street in London. In this demonstration, he had not yet obtained adequate half-tones in the moving pictures, and only silhouettes were visible.

In the first week of October, 1925, Baird obtained the first actual television picture in his laboratory. At this time, his test subject was a ventriloquist's dummy, Stooky Bill, which was placed in front of the camera apparatus. Baird later recollected,

"The image of the dummy's head formed itself on the screen with what appeared to me an almost unbelievable clarity. I had got it! I could scarcely believe my eyes and felt myself shaking with excitement."

After much discussion with his business associates, and further improvements, Baird decided to publicly demonstrate television on Tuesday 26 January, 1926, again at Selfridge's department store. This was the first opportunity for the general public to see television. The Baird company continued to publicize this historic demonstration, and J. L. Baird's other scientific breakthroughs as they feverishly worked to obtain financial backing and construct a line of home receivers.

With Baird's transmitting equipment, the British Broadcasting Corporation began regular experimental television broadcasts on September 30, 1929. By the following year, most of Britain's major radio dealers were selling Baird kits and ready-made receivers through retail and by mail order.

also....

Baird Projection Television, c. 1935

Television Shown In Theaters

"Television in theaters, already a success in England, may soon entertain American audiences. Just opened in a New York office building, a demonstration 'theater' exhibits the Baird system used abroad, which throws brilliant images as large as fifteen by twenty feet upon the screen. Installed in a number of British theaters, it offers televised news scenes to supplement regular movie shows, and all-television shows of major sporting events. Occupying the center of the theater, the projection booth contains all the essential apparatus and controls, except for a special receiving aerial on the roof and high-tension power supply from a 50,000 volt rectifier. One of its two receiver-projectors serves as a stand-by, in case of tube failure, while the other is in operation. Each set employs twenty-seven tubes, including a cathode- ray tube of new design, whose intensely bright four-by- five-inch image is magnified by the projection lens. From the same booth, the operator controls the accompanying sound and all the stage lights."

Onosko, Tim, Wasn't the Future Wonderful?, Dutton (p. 88)


Specific Systems : 1928 - 1932


The General Electric Octagon, 1928 (U.S.A.) with RCA radio 1928 (U.S.A.)

This mechanical television receiver was built for a 48- line television system developed during 1927 by Ernst W. Alexanderson, who was the Chief Consulting Engineer at the GE laboratories in Schenectady, New York. An elaborate experimental transmission on this type of receiver was internationally recognized as the first television drama.

Entitled "The Queen's Messenger", the play had two characters, with only the heads or the hands of the four actors visible at any one time. Two actors spoke the lines, while the other two acted as "hand models". The transmitted signal was received on a console radio and monitored through the 3" lens on the Octagon by the director, and the actors were only a few feet away. GE considered mass-production of the Octagons, but this never materialized.

Daven Tri-Standard Scanning Disc, 1928 (U.S.A.)

The lack of a common standard of picture definition contributed to the demise of the mechanical television boom of the late 1920's and early 1930's. One solution was to make a television set that could receive a number of different standards. This Daven unit was based on a large 24" disc capable of scanning three different standards of picture definition, 24-line, 36-line and 48-line, enabling the viewer to receive more stations.

The television signal was received by a short-wave radio. The operator then had to adjust the height of the neon lamp to match the correct spiral of holes, and synchronize the rotation of the scanning disc to the corresponding rotations per minute. The tiny picture would be visible in one of the three frames (marked within the black outline).

Homebrew W1IM Scanning Disc, 1928 (U.S.A.)

This home-made scanning disc television unit was built by the Connecticut radio experimenter, Clifford Fraser, using hand-written instructions sent to him by the mechanical television pioneer and broadcaster, Charles Francis Jenkins.

Jenkins was aware that "Radiovision" was in its infancy and actively encouraged involvement, experimentation and the exchange of information within the amateur radio community. In the late 1920's, he even went so far as to offer Radiovisor Kits similar to this one at $7.50 U.S. postage paid - a price so low that it meant a loss for his company.

Jenkins Model 202 Radiovisor, 1929 (U.S.A.)

This mechanical scanning-drum unit was engineered, designed and manufactured by the Jenkins Television Corporation, a company founded in 1928 by the American television pioneer, Charles Francis Jenkins. As early as 1894, he presented an article in the periodical, Electrical Engineer, on a method of electrically transmitting pictures. He was one of the earliest to succeed at television transmission, and claimed to have executed the first reported transmission of television by radio in 1923.

Hugo Gernsback of Radio News and Watson Davis of Popular Radio witnessed a demonstration in the same year. In 1928 Jenkins announced the birth of a new entertainment industry, "Radio Movies". Shortly thereafter, Jenkins Laboratories Incorporated initiated 48-line silhouette broadcasting through regularly scheduled telecasts over station W3XK and a few other stations that showed "Radio Movies". Jenkins preferred the term "Radiovision" to "Television", which explains this unit's name.

Baird Televisor, 1930 (U.S.A.)

The Plessey model was the most popular version of the mechanical "Televisor" to be available to the British and West European retail buying public. It was engineered and designed by John Logie Baird and manufactured by the Plessey company in England. It was purchased by television enthusiasts to watch the periodic Baird Studios/BBC broadcasts available from 1929 to 1932. The 30 line images did not take up the entire "screen," but were in fact 6cm high and 2cm wide. Instead of black and white, they were black and red due to the colour of the neon gas in the lamp.

About 1,000 of these sets were originally produced and priced at just over 18 British pounds each. There were kit receivers without the tin cabinet, available from Baird's for only 7 pounds. Baird was one of the true pioneers of television. He successfully demonstrated the possibilities of the Nipkow system of mechanical television by achieving the first television picture in October, 1925.

Western Television Corporation Visionette, 1932 (U.S.A.)

Western Television Corporation played a significant role in the evolution of television in North America. Canada's first experimental television station, which was operated by the Montreal newspaper La Presse and radio station CKAC, was supplied with Western Television equipment. The Canadian public witnessed Western Television's technology through a special mechanical projection apparatus, which was demonstrated at Eaton's and department stores in Toronto, Montreal and Winnipeg during 1933.

In the U.S., Western's travelling demonstrations included a 9-day run at Macy's in New York that was witnessed by over 200,000 people. The Western Television Corporation drew on the talents of television pioneer Ulysses A. Sanabria, who is known for his use of interlaced scanning. Interlacing improved picture quality by reducing flicker. This television utilizes an interlaced aluminum scanning wheel and 3" magnifying lens. It was among the last and most advanced mechanical home televisions to be in use before the electronic sets began to show greater promise.


The MZTV Exhibition "Watching TV"
http://www.islandnet.com/~ianc/dm/11/114.html [This site is no longer in existence:]

"The Royal Ontario Museum's Institute of Contemporary Culture in association with the MZTV Museum invites you to join us for an historic demonstration of BAIRD TELEVISION, live at the Museum, Sunday April 14th, 1996, 1:00pm."

An exerpt from Watching TV: Opening the Doors of Reception by Liss Jeffrey, Acting Director, MZTV Museum. Technical research by Gary Borton, Consulting Curator, and Iain Baird, Researcher, MZTV Museum.

John Logie Baird is the Scottish inventor who obtained the world's first real television picture in his laboratory in October, 1925, and demonstrated it to the British public on January 26, 1926. The image obtained was a small 30-line vertically-scanned red and black image, but it was television. Mechanical television based on Baird's systems dominated international television for the next few years into the early 30's.

The first live public demonstration of a Baird Television system in North America since 1932 will take place in Toronto on Sunday, April 14th. John Logie Baird's son, Professor Malcolm Baird, will give a short speech to commemorate the 70th anniversary of the first public demonstration of television; grandson Iain Baird, who presently works at MZTV, will be in attendance to operate the Televisor.

Mechanical systems of this period are not compatible with today's TV signals. When the MZTV Museum decided to restore this televisor to full operation, the first obstacle was to feed a signal to it that it could receive. We requested the assistance of Peter Yanczer, a modern-day mechanical television enthusiast, author, and technician. He built a mechanical camera that would work on a 30-line system, and connected this camera to the television with cables. The televisor itself needed only minor repairs and lubrication, and has remained workable.

By 1930, a British or West European television enthusiast could buy this televisor for home reception for about 18 pounds. The Baird company was licensed to provide intermittent broadcasts from the BBC transmitters, and at least 3,000 enthusiasts "looked in" to see as well as hear some of Britain's most popular singers and comedians.

Watching TV : Catalog from the exhibition held in September 1996 at the Royal Ontario Museum. The catalogue is? (was in 1996), available from Royal Ontario Museum shop's City Store 299 Queen Street, West, Ontario, Canada. Cost - $11.50 Cdn., $10.00 US, plus shipping. eMail orders: mztv@bravo.ca


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