What’s Keeping Television Out of your Home? (May, 1931)
What’s Keeping Television Out of your Home?
Why hasn’t television achieved popularity as a means of home entertainment? Here’s an authoritative article on television’s present status that outlines the reasons for delay in public acceptance.
by J. EARLE MILLER
FOR four years the radio world, as represented by several million American homes, has been waiting for television. With a number of stations now transmitting radio television programs on schedule, together with a decided indication of real showmanship about to replace haywire experimentation, the average household is waiting in readiness to consider radio-vision as something more than a passing news item. But what equipment is necessary? What stations are broadcasting? Most of all, what is delaying the ultimate popularity of television? Such questions are becoming commonplace.
For nearly two years now a few broadcast stations have been giving picture programs on regular schedules. At the turn of the year there were no less than nineteen television transmitters in more or less regular operation, with outputs ranging from 100 to 20,000 watts. But at the same date, according to the best estimate of television manufacturers in a position to know, not more than 10,000 American homes were equipped with television receivers.
I have just returned from a 2,000-mile trip, visiting all the principal television laboratories and factories in the east, to find out, in the interest of Modern Mechanics and Inventions readers, what they have to offer.
I saw several demonstrations of radio transmitted pictures better than anything that had been dreamed of a year ago. I saw a simple radiovisor kit which solves the old problem of keeping the receiver synchronized and in step with the transmitter, .and makes possible well nigh perfect reception of pictures from a station at any reasonable distance. And, over a land wire circuit, I talked with a man several miles away and saw him face to face as we chatted—a marvelous demonstration of two-way television, for he saw me as clearly at the same time.
I saw compact, well developed apparatus, not much larger than a movie camera, with which out-of-door scenes can be picked up and transmitted, using only natural sunlight to “see” the image. I saw a new system of television reception which has no scanning disc or motor, and no mechanical moving parts. And I was shown letters from nearly every section of the country reporting good reception of broadcast pictures on receivers built from kits ranging in price from $7.50 up to $42.50, and on manufactured sets selling at around $100 to $150 or $175.
That’s the picture of what is actually being done.
On the other hand the “big three” of the electrical world—General Electric, Westing-house and A.T.&T.—as represented by their radio entertainment division, R. C. A.Victor, say that television is not yet ready to be placed in the public’s hands, and that view apparently is also held by the Radio Commission at Washington.
And there lies the real reason why the country is not studded with television transmitting stations, and why television receivers are not found, perhaps, in millions of homes. For the government continues to class it as an experiment and will not permit the broadcasters to sell time for advertising purposes, as they do on their speech broadcasting stations. And without some form of revenue only a few stations have been willing to invest in short wave transmitters and all the other apparatus needed for television, and undertake to develop suitable programs for visual entertainment.
Some of the independents in the field claim the “big three” group not only is withholding its own television developments from the market, but is exerting various forms of pressure on broadcasters to keep them from installing systems which are being marketed.
Regardless of whether such pressure exists, there is no doubt that capital to extend television transmission will not become available in any large sums until the government radio commission removes the ban on commercial television programs and allows the new art to be put on a money making basis. The present ban not only affects the extension of television facilities, but handicaps the broadcast of programs over such facilities as are available.
The 1,000 watt experimental television transmitter operated by the Chicago Daily News station, WMAQ, in connection with its speech broadcast on the higher wave band, is a case in point. President Hedges, of WMAQ, would like to develop programs employing dramatic talent, with paid actors in suitable costume plays, and other new types of visual entertainment. But until the time on the air can be sold to advertisers the money is not available to pay entertainers, buy costumes, and stage spectacles which might rival moving picture entertainment.
The Daily News broadcasting officials are enthusiastic over the results already attained with the 1,000 watt station, which operates on a 45 line scanning system, using three spiral rows on the scanning disc. They believe it is far superior to the more common forty-eight, single row system, for it eliminates flicker. Letters have been received from points as distant as Cincinnati, Oklahoma City, St. Louis, and Albuquerque, N. M., reporting excellent reception of the short wave pictures with the accompaning voice on the normal broadcast band.
So much for the situation of television today. If you want to get into this most fascinating form of home entertainment, here is what you will find: You can buy a manufactured picture receiver and a manufactured short wave receiver, specially designed for its purpose, or buy any of several different kits, for either picture receiver or short wave radio set.
To pick up the existing nineteen transmitting stations you need a short wave radio set covering the wave band from 2,000 kilocycles up to 2,950 kilocycles, or from about 100 meters to 150 meters. In the 2,000-2,100 band (television so far is operating on hundred cycle bands instead of the ten cycle range between the longer wave speech broadcasting stations) you will find six stations, three of 5,000 watts power, and one each of 500, 250 and 100 watts. The three 5,000 watt stations are located at Wheaton, Md., New York City and Passaic, N. J., the first being operated by C. Francis Jenkins Laboratories and the other two by the Jenkins Television Corporation and DeForest Radio Company, which are closely related and are using many of the Jenkins patents.
In the next band, 2,100-2,200 kilocycles, there are seven stations, including the 20,000 watt transmitters of the Westinghouse and General Electric companies, two 5,000 watt stations of the National Broadcasting company, the 1,000 watt Chicago Daily News Station and the 500 watt transmitters of the RCA-Victor group and Radio Pictures, Inc.
The two shorter wave channels available for television by Federal order lie between 2,750 and 2,850 kilocycles, and 2,850-2,950. In the former there are three experimental stations operating at no stated intervals, and in the latter band three, of which two, with 500 watt power, operate on set schedules; and the third, a 5,000 watt plant near Chicago, has no regular hours.
That covers the radio broadcast end of television. To transmute images into electrical energy which can be transmitted through the air or over wires engineers use an instrument variously described as a televisor or a radio-visor. The former term really should only apply to pictures sent by wire, but television has be- come so generally used that it is applied to radio pictures also. The picture reproducers so far on the market vary in type but are the same in principle. Pictures are being broadcast with 24, 45, 48 or 60 lines to the inch, while the Bell Telephone laboratories, in their demonstrations of two-way television by wire, use 78 lines. Various broadcasters also trans-] mit varying numbers of pictures per second, the more common numbers being fifteen and eighteen.
The receivers all use a neon glow I lamp to take the output of the short wave receiver, a scanning arrangement consisting either of a disc or a I drum with holes through which the i light beams pass, and an enlarging lens to increase the apparent size of the image and make it possible for several people to see it at one time. The biggest problem is turning the disc at the exact speed of the scanning disc at the transmitting end, and keeping the two in perfect synchronism. If your receiver is located in the same town as the transmitter, and both receive their motor power from the same electric light company the problem is not serious, for the two 60 cycle motors will operate at the same speed. But to get signals from a distant station and transform them into images it is necessary either to provide some means of manually correcting the speed from time to time, or else some electrical agency to do the same thing.
In one of the simplest kits, produced by the Jenkins Laboratories, the disc is driven by a rubber tip on the end of the motor shaft, and the motor itself can be moved back and forth by turning a screw feed. As the motor is moved outward from the disc center the disc naturally revolves at a slower rate, and as the motor moves inward it speeds up.
In another type of set, manufactured by the Jenkins Television Corporation—which has no connection with Mr. Jenkins’ own laboratories beyond the fact that it uses his patents—synchronization is attained by filtering out a portion of the incoming signal, amplifying it, and using the product to operate a phonic motor, which keeps the receiver in exact step with the transmitter. If the system used at the broadcast end produces 15 pictures per second of 48 lines each, there will be a strong 720 cycle frequency present in the incoming signal—48 times 15 being 720. A special tube in the short wave receiver picks out this frequency and amplifies it.
For the receiving end, engineers of the Westinghouse Laboratories at East Pittsburgh have developed, after considerable experimental work, a television system which has no mechanical moving parts. The incoming signal is delivered to a cathode ray tube, releasing a stream of electrons which, due to a fluorescent material within the tube, appear as an image on the end of the tube. So far tubes with an end diameter of about nine inches are the largest that have been made. The electronic bombardment can be diverted from its path by a magnet. The sine wave sweeps the image across the tube horizontally, and a magnetic field is used to paint the picture in successive parallel lines. In television with a scanning disc or drum, the lines sweep always in one direction, but with the cathode tube the picture is painted both ways, as though you drew a pencil back and forth across a sheet of paper without lifting the point. With this system television has been produced with as many as 120 lines to the picture.
The fluorescent material used in the tube gives a bright green image, in marked contrast to the familiar pink or red glow of the neon tube used in other systems.
When the “big three” divided up their spheres of activity and assigned all entertainment features of radio and television to the RCA-Victor organization, the A. T. & T. retained the commercial development of wired pictures in connection with telephones, and the Bell Laboratories has recently demonstrated successful two-way television over the telephone wires.
While the apparatus is still in the laboratory stage, it is possible that it may be offered the public within another year or two as a special form of telephone communication. If that time comes, people wishing to both see and talk at long distances will make appointments in advance and appear at the set time at the nearest television stations, where the connection will be established, and they will then be seated in the booths. Telephone apparatus of the usual type is eliminated. A microphone concealed in the cabinet takes the place of the telephone transmitter, while the receiver is replaced by a loud speaker so situated that the voice seems to come from the lips of the image. The image size gives the appearance of a person about fifteen feet away, and the amplification in the loud speaker is regulated to that of a normal voice speaking at the same distance.
That is the status of television today. If you live most any place east of the Rockies you can pick up the signals of one of the nineteen existing stations located in Illinois, New York, New Jersey, Pennsylvania or Maryland. You can get interesting pictures and “grow up” with the new art, just as the original radio fans helped develop radio to what it is today. You can have your choice of home-built short wave receivers and televisors, or buy ready manufactured sets. If you want more information about specific sets, prices, etc., Modern Mechanics will be glad to tell you where to get it.