THE RADAR RECEIVER 



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an airborne radar low-altitude bombing equipment as employed extensively 

 during the past war. Here the display employed is of the B variety utilizing 

 a 5" long-persistence cathode-ray tube. The focussing and centering 

 magnetic fields here are produced by coils located as shown. The azimuth 

 sweep voltage is obtained by means of a potentiometer mechanically geared 

 to the sector scanning antenna. The permanent off axis deflection of the 

 zero range line of the B display is here obtained by the use of a permanent 

 magnet yoke mounted at the junction of the neck and bulb of the cathode- 

 ray tube. 



Figure 46 illustrates a typical form of an A-type indicator as developed 

 for the SH Naval and Mark 16 mobile fire-control radar equipments. This 

 unit includes provision for receiver tuning and video limiting adjustment 

 convenient to the observer. The SH and Mark 16 radar systems employ 



Fig. 45. — Mechanical design of AN/APQ-5 type B radar indicator. 



both lobing of the antenna for precise azimuth bearing determination and 

 also continuous rotation of the antenna for general search purposes. The 

 indicator shown in Fig. 46 is employed when the lobing system is in opera- 

 tion and features a precision range sweep as well as the full range display. 

 The ecjuipment design here reflects the severe mechanical requirements 

 which must be satisfied for electronic equipment which is to be employed on 

 naval vessels or for trailer mobile ground service. 



2.5 The Radar Siveep Circuit 

 2.51 Function 



The sweep circuit components of a radar receiver are required to generate 

 the specific voltage or current wave forms necessary to properly display the 

 radar-received information in the desired form. These wave forms must 

 also be actuated by or related to the various coordinate or computed types 

 of data furnished to the radar receiver. The actual detailed configuration 

 of the circuit cmi)loyed for this purpose is dependent on the form of the input 



