THE WORLD'S ADVANCE 



263 



Sixteen years have elapsed since the English Channel exper- 

 iments, and the meaning of "long distance" wireless com- 

 munication has been constantly altering on an ascending scale. 

 Today a long distance radio station can send and receive mes- 

 sages thousands of miles: the Arlington station keeps in touch 

 with the Pacific coast stations; the Eiffel Tower station in Paris 

 communicates with stations in Russia; the powerful Marconi 

 stations in England, which have been taken over by the British 

 Government, transmit orders to Warships in the distant Me- 

 diterranean and, perhaps most remarkable of all, the Nauen and 

 Eilvese stations in Germany permit of communication with 

 the outside world. 



serious hindrance to stations working on 

 other wave lengths. 



Within the past several weeks the 

 Tuckerton station has been engaged in 

 making comparative tests between Tuck- 

 erton and Eilvese of the arc and Gold- 

 schmitt high-frequency alternator. In 

 fact, they have been alternatively em- 

 ployed through the days' schedule. It is 

 generally understood as a result of these 

 tests that the arc set carries further than 

 the high-frequency generator, but the 

 note produced by the arc has no where 

 near the purity of that obtained by means 

 of the generator. 



In the third method referred to at the 

 beginning of this article, viz., the high 

 speed, high-frequency alternator, outside 

 of experimental laboratories it has not 

 been employed for commercial work. 

 The initial speed of this machine is so 

 high (20,000 r. p. m.), that they are not 

 yet considered as a commercial proposi- 

 tion. 



The General Electric Kenotron is a 

 new-comer in the field of radio tele- 

 graphy, and is, in fact, a special form of 

 vacuum valve oscillator comprising a 



hot filament and a cold plate placed in 

 vacua. When a direct current is made 

 to flow between the filament and the 

 plate and is in turn shunted by an in- 

 ductance and capacity, the Kenotron be- 

 comes a generator of undamped oscilla- 

 tions, which may in turn be transferred 

 to an antenna circuit by means of an 

 oscillation transformer. The Kenotron 

 is exhausted to the highest possible de- 

 gree practically a perfect vacuum is ob- 

 tained. At the present writing the out- 

 put of this type of undamped generator 

 is limited, but future experiments may 

 reveal that a number of these can be 

 placed in parallel, and if so it will prob- 

 ably take the place of the high-frequency 

 alternator or the Poulsen arc. 



It would seem from a review of the 

 various systems just described that we 

 are on the eve of important develop- 

 ments and extensions of long distance 

 radio service and that within the very 

 near future a number of extremely long 

 distance radio circuits will be available 

 for communication with foreign coun- 

 tries, giving the same degree of accuracy 

 as the ordinary cable. 



TIFFIN RADIO CLUB 



The Tiffin Radio Club has recently 

 been founded at Tiffin, Ohio, and the fol- 

 lowing officers appointed: 



President, John J. Grossman ; Vice- 

 President, Paul E. Fredericks and 



Secretary-Treasurer, Harold C. Buck. 



All the members of the Tiffin Radio 

 Club have stations. 



All correspondence to the club should 

 be addressed to the President at 181 

 Hudson Street. 



