810 BELL SYSTEM TECHNICAL JOURNAL 



AGC circuit design is dependent to a major extent upon the dynamic 

 characteristics of the associated automatic tracking device. The subject 

 of automatic tracking design principles cannot be reviewed here and accord- 

 ingly more detailed AGC design consideration must also await inclusion in 

 such a future report. 



2.8 Radar Receiver Power Supplies 



The remaining components of the radar receiver to be here reviewed con- 

 sist of the power supplies necessary to produce the various d-c potentials as 

 required for the operation of the electronic components of the receiver. The 

 principal design problems associated with these components arise from the 

 relatively poor stability characteristics of the prime sources of power avail- 

 able at the military scene and the rather severe output voltage requirements 

 to adequately serve the precision nature of radar reception, display, and 

 measurement. The supply voltages necessary for a military radar receiver 

 range from low bias potentials upward to 5000 volts for cathode-ray tubes 

 and TR application with both polarities often required. 



2.81 Primary Power Sources 



The characteristics of the primary source of power available for the mili- 

 tary radar system are dependent on the area of use of the equipment. In 

 the case of mobile ground radar installations, the gasoline engine driven 

 generator represents the typical primary power source. In the case of large 

 mobile radar systems it is customary to employ ILS-volt — 60-cycle primary 

 power, while in certain more portable designs 115-volt — 400-cycle primary 

 power has proven satisfactory. The frequency and output voltage of a 

 gasoline engine driven alternator cannot be maintained within the narrow 

 limits desired by the radar receiver and here the major burden of precise 

 voltage regulation must be carried by the electronic regulated power supply 

 within the radar receiver. 



For naval vessel radar installations 115-230-volt — 60-cycle primary power 

 is commonly available on the larger vessels. For PT and similar smaller 

 craft, certain radar installations have been employed operating from 24-48 

 volts direct current with motor generator sets supplying 60-cycle or 400-cycle 

 power for the radar system. In the case of undersea craft, the storage 

 battery is em])loyed as a primary source of ])ower and motor generator sets 

 are employed to obtain 115 volts, 60 cycles in most instances. 



The primary source of ])ower for aircraft radar purposes is either a low 

 voltage (27 volts) d-c generator driven by the aircraft engine or an alter- 

 nator similarly driven. If d-c power is available, an additional motor gen- 

 erator set may be emj)loyed to furnish the 115-volt — 400 to 800-cycle power 

 for the radar equipment use. Voltage regulators of the carbon pile compres- 



