New York Herald, October 8, 1911, page 12:
BOY EXPERTS IN WIRELESS TELEPHONING
Members of Junior Wireless Club Take Up New Form of Scientific Sport.
"JUST listen to that," remarked a member of the Junior Wireless Club of New York city as he transferred the receiving apparatus from his own head to that of a visitor. "There's some wireless telephone music for you." And sure enough, with as much distinctness as though the phonograph were in the room the strains of a stirring military march came in wireless waves from the home of another club member, some four or five blocks away.
Not only were the musical notes transmitted, but the voice of the operator was heard with equal distinctness. Distance has been destroyed by the wireless telegraph, but time has been saved by the wireless telephone, for the difference between sending even a short message by either the Morse or Continental code, such as that used in wireless telegraphy, and the time it takes the speaking voice is, as any one can readily see, appreciable.
To be able to talk without wires and without the use of the arbitrary signs used in wireless telegraphy, or, in other words, radio-telephony, is the subject which is engrossing the boys of the Junior Wireless Club just now, as indeed all experts in the science. In the wireless station of the club, which has been fitted up in the rear of the home of Frank King, corresponding secretary, at No. 326 West 107th street, New York--which by the way, was almost wholly equipped by George Eltz, the vice president of the club and one of its cleverest members--the problems of radio-telephony are being studied, and to a great extent solved.
As a result, the members can talk with one another at a distance of a quarter of a mile, which compared with the claims of inventors like Valdemar Poulsen, of Denmark, who asserts his ability to talk 900 miles, may seem an insignificant success. But it does prove their understanding of the principles, and it only needs more experience, say the amateurs, to enable them to talk at least twenty-five miles away, which is the average distance covered by the government war ships.
"Marconi was once an amateur," is the unwritten slogan of the club, and many failures have been turned to success by the thought that the world famed inventor was once upon a time a modest aspirant for electric knowledge even as they.
According to Frank King, it is more in the sending apparatus than the receiving that the greatest difference in the equipment of wireless telephony lies.
"The receiving in wireless telephony," he explained, "is practically the same although it is very necessary to have a good wireless receiver in order to get returns. One must have a very sensitive detector, for otherwise, though you may be able to get the wireless messages rather clearly, you wouldn't be able to get the telephone at all.
"Now, the sending apparatus is totally different. Instead of an induction coil and spark you generally have an arc light with a high frequency, and this high frequency is generally increased by putting hydrogen in the arc. The frequency of the arc has to be within the range of the voice, and by means of an induction couple the energy is transmitted to the aerial and the ground.
"As a rule the transmitter is in some way connected with the primary current to directly influence the arc or by an inductive means to influence the secondary current going into the aerial and the ground. The difference between the ordinary arc and the arc used in wireless telegraphy lies chiefly in the fact that a condenser is shunted around the arc, and this, becoming charged and discharged across the arc, gives it a high frequency. The leads supplying the current to the arc should have choke coils, one for each lead.
"To make a simple wireless telephone for a beginner there must be a direct current of 110 volts first, which, however, should be reduced to five amperes or less. This current is connected with an arc through two choke coils, as per diagram. The arc consists in having a copper terminal on one end and a carbon on the other. By means of a small water jacket around it the copper terminal should be kept cool, the water being continuously supplied by means of a syphon arrangement
"A condenser of about one M. F. should also be shunted around the arc through the primary of an inductance. This should consist of about ten turns of No. 16 wire, each turn about a foot long. The wire in the secondary can be about the same length, this to be determined by experiment. It all depends on the amount of current and the kind of apparatus used.
"Any standard transmitter, as used in ordinary telephony, may be used. This is generally inserted in the secondary circuit which, as shown by the diagram, is connected with the aerial and the ground. The position of the transmitter may be varied perhaps with better success once experience has been gained, but this is a good method and has the advantage of simplicity.
"If the secondary current is so strong, which is very unlikely, as to harm the carbon granules in the transmitter, a small telephone induction coil with batteries should be put in, so the danger may be obviated. Hydrogen may be supplied by means of a small alcohol lamp placed beneath the arc."
Since the Wireless Club was started some five years ago with W. E. D. Stokes, Jr., at its head--and who, by the way, is still its president--the fourteen members have solved many problems in wireless telegraphy. Along with other amateurs they have reached and maintained conversation with Key West Fla., and Glace Bay, Nova Scotia, and many improvements to the apparatus have been invented and patented by the more expert of the boys. George Eltz has been particularly successful in his respect, and his wireless telephone outfit which is now in use is said to possess a number of valuable improvements.
It was for the purpose of preventing any legislation unfavorable to amateurs that the club was first formed, and within a year a large delegation of the boys, headed by W. E. D. Stokes, Jr., went to Washington and spoke against a bill introduced by wireless companies to force amateurs out of the field, or, in other words, to prevent their "butting in" to commercial or government communications.
To be eligible to the Junior Wireless Club each boy must have an instrument of his own--that is, he must know how to construct one and must be familiar with the Morse and Continental codes. At the monthly meetings one of the members gives a short talk on wireless matters. He usually describes some improvement in the equipment he is working out or some problem he may have solved. Thus each boy gets the benefit of the other's knowledge as light is thrown on puzzling questions.
Any one of the boys is eligible to act as operator, or would be after passing government and a United Wireless test, which they are quite capable of doing, did they wish to becomes wireless operators. As a matter of fact, there many operators in service to-day who know nothing about the construction of the instrument or what to do in case of accident. Nearly any one who understands telegraphy can operate a wireless instrument, though he would be useless to repair it.
In the midst of the recital of the club's history came the secretary's wireless called "H. M." Donning receivers, we heard through space from a quarter of mile away strains of music, selections from "The Spring Maid," which was followed by an animated conversation between the two amateurs relative to some contested points in radiotelephony.