b. Reception Factors 



(1) Adaptability to auto control: development appears to be practical 

 but auto control not available at present, 



(2) Fail-safe feature: system is fail-safe, A failure in transmission 

 of the ground station is apparent at the receiver if it is properly 

 monitored. No system error is introduced by a malfunctioning 

 receiver. 



(3) Circuit types employed and circuit peculiarities: Keyed cw trans- 

 missions. Character count at receiver determines LOP. Com- 

 munications receiver only required. Specialized narrow-band 

 equipment would increase reliability range and utility of the system. 



(4) Uncertainty of LOP: 1/3 - 1° in the largest percentage of the 

 coverage area. 



(5) Special chart requirements: special charts which are relatively 

 easy to prepare and use are required. 



(6) Security: service cannot be denied and is useful to friend and foe 

 alike, 



(7) Adaptability to recording: strip chart recordings quite practical. 



(8) Reliability: high; only a standard communication receiver is 

 required, 



(9) Range: 25 - 50 nautical miles minimum to 1000 - 1400 nautical 

 miles maximum range. 



c. Transmitting Factors 



(1) Transmitter power: 1-3 kw used in each of the transmitters 

 required per ground station. 



(2) Antenna requirements: three top -loaded vertical antennas, 

 300-650 feet high. 



(3) Complexity of ground equipment: transmitters are standard cw 

 rigs. In addition, automatic keyer phase shifter and matching 

 units are used. 



(4) Reliability: high degree of reliability is apparent because of lack 

 of complex equipment. 



(5) Station operator requirement: automatic operation possible. 

 Maintenance requirements similar to standard cw stations of 

 this power. 



43 



arthur ai.lLittlc.ilnr. 



