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BELL SYSTEM TECHNICAL JOURNAL 



and a good many of them tried. Considerable further work is under 

 way. 



At the time when the short waves are in trouble apparently either 

 one of two conditions may obtain. In the first of these there may be 

 considerable field received from the distant transmitting station but 

 this field is made up of the result of transmission over several paths so 

 that the waves received over the different paths react on each other, 

 causing a rapidly fluctuating interference pattern somewhat similar to 

 that well known with light waves. 



There are other times, however, when either the field which reaches 

 the receiving point is not of sufficient magnitude to be picked up or is 

 below the static noise level at the particular time. 



One interesting fact with these very short waves is that the ignition 

 system in automobiles may create large disturbances and it is important 

 that the receiving points should be kept away from roadways fre- 

 quented by automobiles. For this and other reasons the New Jersey 

 location will undoubtedly be moved somewhat from ClifTwood. 



RADIO TRANSMITTER 



RADIO RECEIVER 



RADIO RECEIVER 



RADIO TRANSMITTER 



Fig. 12 — Indicating diagrammatically east and west transmission on separate channels 

 terminated in ordinary transmitters and receivers 



So much then for the question of the radio circuits themselves. The 

 problem remains of making them serve as a link between the two-wire 

 systems on the two sides of the Atlantic. If the problem were merely 

 transmission from one particular subscriber's set to another particular 

 subscriber's set, the very simple arrangement shown in Fig. 12 would 

 be feasible. In this you will note the eastbound and westbound trans- 

 mission each starting with a telephone transmitter at one end and ex- 

 tending to a telephone receiver at the other are kept entirely separate. 

 Two people could evidently carry on a conversation over this circuit 

 without further complications. In fact this was the way in which the 

 first two-way tests were carried out. 



