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BELL SYSTEM TECHNICAL JOURNAL 



In general, three wavelengths are used, one around 19,000 kc. (16 

 meters), one around 14,000 kc. (21 meters) and one around 9,000 kc. 

 (3v? meters), and each transmitter and receiver is arranged so that it 

 can be connected at any time with a directive antenna designed for 

 each of these frequency ranges. The transmitter antenna gains are 

 about 17 db over a one-half wave antenna. These short-wave radio- 

 telephone facilities which connect the American telephone network 

 with Europe and South America have already been the subject of 

 technical papers ' and need not be described in further detail. An air 

 view of the Lawrenceville, N. J., transmitting station is given in 

 Fig. 5. The longer of the two lines of towers supports the antennas 



Fig. 5 — ^Lawrenceville transmitting station. Aerial view — -South American an- 

 tenna in the foreground; European antenna in the background. Two buildings 

 each containing two transmitters are shown. 



for the three short-wave circuits to England, and the shorter line of 

 towers the antennas for the single circuit to the Argentine. Some idea 

 of the magnitude of the plants emplo>ed for these short-wave circuits 

 may be had from this photograph. The longer line of antennas is 

 approximately one mile long, consisting of twenty-one 185-ft. towers. 

 Substantial fireproof buildings are provided for the transmitting sets 

 and auxiliary equipment. Probably every operating agency which has 

 ^ See bibhography. 



