TRANSOCEANIC TELEPHONE SERVICE 



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wave lines consist of short lengths of pipe mounted on frames under the 

 antenna curtains as shown in Fig. 5. 



Transmitting Station 



Among the first radio problems encountered in the design of a trans- 

 mitting station for several channels are those concerning the size, 

 shape, and number of antennas, their directions of transmission, their 



Fig. 5 — Section of antenna system at Lawrenceville, showing lower portion of 

 curtains and quarter wave transmission lines used as transformers and anti-resonant 

 circuits. 



relative positions from the point of view of mutual interference, and 

 their grouping around the transmitters. 



The number of antennas required for each channel is determined by 

 the hours of operation and the average grade of service which the sys- 

 tem is expected to render. For service covering a large portion of each 

 day several wave-lengths are necessary. Transmitters Nos. 1, 3, and 4 

 at Lawrenceville each are assigned three frequencies. No. 2 has five 

 assignments in order to improve the likelihood of at least one channel 

 being available throughout the entire day at all seasons. 



The size and shape of the antennas are, of course, determined by the 

 directivity wanted, by the type employed, the frequency assignments, 

 and by considerations of cost. They are governed also by the necessity 

 of connecting several antennas to the same transmitting set. This 

 involves both the spacing and arrangement of antennas to avoid 



