Wireless Wonders Worked In San Francisco (1912) > 자유게시판

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It is an interesting indisputable fact that the brand new South San Francisco station, geared up for a daily enterprise with Honolulu as well as inland factors, uses only one thirtieth of the electric power needed to function the spark system between the coast of Newfoundland and Ireland, which is about 400 miles the shorter distance. The potentialities of the Poulsen system had been early seen by C. F. Elwell, a Stanford graduate who had specialized on wireless issues. Mr. Elwell, as long as two years in the past, carried on wireless conversations from Stockton to Sacramento, a distance of 50 miles overland, and his dialog was overheard at Palo Alto, eighty five miles away. In the first place there are the 2 masts, at the present time the tallest on this planet. At current messages are carried into Chicago via the smaller and therefore much less efficient stations of El Paso and Fort Worth. Yet there are different disturbances fairly as serious. There are other curious happenings of a milder form and not much less romantic. These poles are about the only factor concerning the place that the uninformed outsider can mentally grasp. The next thing to puzzle the wits of the outsider are the copper coils fastened to the ceiling of the room.

But the results achieved by the Federal people show that distance above sea stage has nothing to do with the case--which is kind of a distinct thing from saying that peak above the floor of the ground just isn't an advantage, for it's a decided one. This generator is about an important factor in the shop. To borrow one other Veeder illustration, if a pistol (which represents the spark impulse) is fired close to an open piano, all the strings are set in vibration; but if a tuning fork be struck, which provides off sound waves of equal length (comparable to these of the Poulsen generator), then only the strings attuned to that observe give out a response. The movements of the wire thus appear on its length as a zigzagging white line. The tape comes prepared with a central line of small holes, the sprint or the dot being punched on its respective aspect of this line. Masts of the scale simply built in new South San Francisco station will soon be positioned in a direct line from here to New York.

But meantime the Honolulu operator took messages from San Francisco without any interruption, which proves the steadiness of the Poulsen waves. But this didn't completely prove the efficacy of the Poulsen system overland, insulated copper cable since San Francisco is by the sea and Los Angeles additionally near it. On account of its "excessive frequency," using the telephone under the Poulsen system is as unlimited as telegraphy itself. The sending price by the spark system is from 15 to 20 words a minute. Poulsen hand sent and the ocean cable run from 25 to 30. The rate of sending and receiving has thus its human limitations. The waves passing over the antenna run into tons of of thousands the second. Between their tips is stretched seven miles of delicate wire feelers, identified because the antenna, which provides off and receives the electro-magnetic waves of the Morse code. This contrivance knocks out from 200,000 to 1,000,000 long, regular waves to the second. These wheels are insulated, except from copper strips set in at regular intervals. The small pins in turn release bigger pins, which function a set of brushes, throwing the present to one in every of three revolving wheels. The duplexer, a rough wanting machine for the delicate work in hand, is a pair of wheels driven collectively by a belt from a motor and touched by copper brushes.

It is an iron field sitting above a pair of big magnetic coils. Contained in the box are a few massive carbon rods set a small house apart, end to finish. This sensitised paper, concealed in a field, is fed as tape from a roll and passes in front of a small hole reverse the lenses. Instead of ready for the wires to clear, the operator sits in front of a punching machine feeding from a roll of tape. Before tape is both despatched or obtained, preparations are made between stations by the bizarre key and receiver. One night time the island operator distinctly caught spark messages despatched by one of the large trans-pacific liners leaving Japan. That's the reason some wireless programs nonetheless work exclusively at night. Finally came the eventful evening when the brand new Federal station at Honolulu was ready to speak for itself. Then got here a lapse, and nothing, was again picked up until the vessel was close to Honolulu.