International projectionist (Jan-Dec 1946)

lock which will require a long time to overcome. There will be very few receivers sold in area? which are not served by at least one television program. On the other hand, broadcasters are generally wrary about investing hundreds of thousands of dollars in television transmitting and studio equipment, etc., when there are no receivers in their service area. The television broadcaster will necessarily take a long chance in investing large sums of money in transmitting equipment and expensive programs for long periods of time before he begins to realize a return on his investment. It will require many farsighted broadcasters and many years to build up a nationwide television sendee. On the other hand, one farsighted broadcaster can immediately create programs for 16 million people by operating one broadcasting airplane. This should greatly advance the production and sale of television receivers and greatly reduce the time required to realize national television coverage. Economic Comparisons In attempting to evaluate economically the operation oi airplanes for broadcasting, it is hard to find a concrete base for comparison. There is such a radical difference in the amount of television service obtainable by operating from airplanes as against operating ground stations that the two systems hardly have a common base. Many things can be readily accomplished by operating from airplanes which will never be accomplished by operating on the ground. It was decided that the best method of economic presentation would be to compare the cost of operating one airplane against the cost of operating the number of ground stations required to give an equivalent coverage. After comparing the two systems on this basis, a list of advantages and disadvantage? which are hard to evaluate is used to supplement the foregoing comparison. Pittsburgh was chosen as a typical operating center, and by filling in the coverage from one airplane, it was found that eleven 50-kilowatt transmitters would be required to service the same area from the ground. Since one airplane serves the area with four television and five FM programs, an equivalent coverage requires 44 television transmitters and 55 FM transmitters, and approximately 33 relay stations. In the cost comparison, it is assumed that the same program is fed into either system so that programming costs cancel each other. The operating cost for one Stratovision station is estimated to be about SI. 000 per hour. The cost for giving an equivalent ground coverage is about $13,000 per hour. This cost comparison does not include the cost of relay stations or coaxial cable required to deliver the program to ground stations, but includes broadcasting cost? only. If relaying costs were included, the ratio would be even greater. Additional advantages are: 1. Elimination of an expensive, inadequate, and slowly built up program distribution network. 2. The sale of television receivers should be greatly expedited. 3. The time required to build television into a nationwide service should be greatly reduced. 4. Many people in small urban and rural districts will have television who would never receive it otherwise because they live in district* which are too sparsely settled to support a station. 5. High-definition color television would immediately be placed on an equal footing technically with present blackand-white low-definition television. 6. The source of program material is greatly increased. 7. Many complicated antenna and '"ghosting" problems can be eliminated because the plane is in continuous motion and all programs will come from one direction at any receiver. Cause of "Ghosting" These "ghosts" are out-of-register pictures superimposed on the desired picture. They are caused by a delayed signal, reflected from a hill or building. arriving at the receiver. They are very objectionable in some areas, such as New ^ ork. Because the transmitting airplane will be free of such reflecting objects, it is anticipated that "ghosting" troubles will be greatly reduced by the Stratovision system. Since all programs will come from one source, the home receiving antenna can be made much simpler and at a lower cost. A fixed directional antenna can be used pointing constantly toward the airplane instead of a complicated motordriven directional antenna to be rotated in succession toward the antenna of each newT ground station from which a program is desired. The fact that the airplane, and thereby the transmitter, is moving w~ould also take advantage of an optical feature wherein the eye does not object to a moving "ghost" as badly as it objects to a stationary "ghost." Radio equipment problems involved in Stratovision are very similar to those with which we have had considerable experience during the war. Almost every feature of the system has been proved by our experience of the last few years. The technical problem involved in putting this system into operation are capable of solution and are easier than those involved in the presently planned system. We feel that the economic problem is much more attractive and that it is the only system yet proposed which will make television available to millions of listeners in rural districts and small towns. Plane Design Data Aerodynamically. planes for the Stratovision system offer no particularly difficult problem. Every known flying aid — radar, navigational, and blind landing equipment — will be provided for in the basic design of the planes. Extreme wind velocities present a problem, but not an insuperable one. The absolute maximum velocity ever recorded w_as 181 miles an hour at 18.000 feet over Lansing. Michigan, in December. 1919. B-29 crews over Japan often reported winds exceeding 150 miles per hour. The Stratovision plane with its cruising speed of 140 miles per hour and high speed of over 225 miles per hour will easily hold its own at 30.000 feet altitude against any wind encountered within continental U. S. limits. It is no exaggeration to say that takeoffs and landings will be accomplished in conditions of zero ground visibility. Indeed, the only condition in which a modern airplane cannot operate is when wind velocities on the airport introduce unwarranted landing and take-off hazards. It is doubtful if a ground transmitter tower will withstand the forces of a tornado, and as a matter of fact, in the 1938 New England hurricane, ground transmitters were off the air. However, with Stratovision broadcasting, the rebroadcast airplane can take off from Chicago outside of the storm area, fly over Pittsburgh at an altitude safely above the weather and serve the area even when a hurricane may have disabled all ground equipment. There are other things which can force the airplane down, such as loss of cabin supercharging pressure, but here again we will use the same technique which nullifies the effects of engine failure, ^e will supply 100^ standby in all such items, including power generating equipment, emergency controls, oxygen and all the other items which make aircraft reliable in war and peace. The airplane, as we conceived it. will require an operation crew of three, including pilot, co-pilot, and radar operator-navigator. The broadcasting equipment will be serviced by six operators. A comfortable lounge will be provided for relaxation. JANUARY' 1946 25