Long Distance Wireless Telegraphy* 



By J. B. Woolsey 



PREVIOUS to the outbreak of Eu- 

 ropean hostilities, the station at Say- 

 ville was engaged in a series of experi- 

 ments with the Telefunken station at 

 Nauen, in Germany. The Sayville sta- 

 tion has since been engaged in the receipt 

 of commercial and official war bulletins 

 from this point, at irregular intervals. 

 The Nauen station (POZ) operates on a 

 wave length of about 9,500 meters and 

 makes use of the so-called Count Arco 

 step-up transformer system for the gen- 

 eration of undamped oscillations. 



This system is of interest because the 

 alternations of a generator having an 

 initial frequency of about 20,000 cycles 

 per second are raised to double or triple 

 this value by means of ingeniously con- 

 structed step-up transformers, each one 

 of which doubles the frequency supplied 

 to its primary winding. The cores of 

 these transformers are magnetized by 

 direct current flowing through a special 

 winding and are thus saturated to a cer- 

 tain critical degree. When in this state 

 of magnetization, alternating current is 

 passed through another winding (which 

 is the primary winding), causing a 

 change of the existing flux that has been 

 produced by the D. C. winding. Thus a 

 single alternation of current will cause a 

 weakening and strengthening of the ex- 

 isting flux, which in turn produces two 

 alternations in the third winding for ev- 

 ery impulse in the primary winding. Thus 

 the frequency is doubled and may be 

 doubled again by the addition of a similar 

 transformer. 



The signals from this station are re- 

 ceived at Sayville on a special form of 

 Lieben and Reisz current relay which 

 in reality is a type of the gaseous valve 

 detector. This relay is fitted with local 

 fixtures, making it a generator of un- 

 damped oscillations which in turn pro- 

 duces the phenomenon of beats from the 

 incoming signals causing an audible note. 



*This is the second portion of Mr. Woolsey's most 

 interesting article on long distance wireless systems 

 and stations. The first half appeared in the July 

 issue of THE WORLD'S ADVANCE. 



The Lieben and Reisz relay is, in fact, 

 a copy of the well-known audion. 



The Sayville station employs a 500- 

 cycle quenched spark transmitter of 35 

 K. W. capacity and cannot send to the 

 Nauen station in the daytime. The oper- 

 ators are therefore required to reply to 

 Nauen's communications during the 

 more favorable hours at night time. The 

 Sayville station employs for this work 

 a wave length of about 4,800 meters. 



Provided static conditions are not 

 severe Nauen's signals can be read 

 throughout the day at Sayville, but the 

 reception of signals at Sayville is not 

 constant. The station is therefore re- 

 quested many times to make repetitions. 



The traffic sent to Nauen from Say- 

 ville is repeated three times to insure ac- 

 curate reception. This route to Ger- 

 many is limited in the amount of traf- 

 fic that may be handled, but nevertheless 

 it is of considerable aid to the Germans 

 while they are cut off from cable com- 

 munication. 



The amateur experimenter who be- 

 lieves that the Arlington station at Radio, 

 Va., is silent during the day may be sur- 

 prised when he finds that this station is 

 at that very moment apt to be in com- 

 munication with the naval station at 

 Point Loma, California. These naval 

 stations are fitted with the Poulsen arc 

 type of transmitter having a capacity of 

 30 or 40 K. W. The receiving apparatus 

 employed for this work is a special form 

 of audion which is particularly suited to 

 the reception of undamped oscillations. 



Communication via this route is quite 

 reliable by day and night, a fair amount 

 of official business being dispatched in 

 both directions. 



The Arlington station also communi- 

 cates by means of undamped oscillations 

 with other naval stations which are fitted 

 with receivers for the reception of un- 

 damped energy. 



A large naval station is about to be 

 opened up at Darien on the Isthmus of 

 Panama. This station is expected to 

 employ a wave length of nearly 20,000 



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