TEE RADAR RECEIVER 



747 



ity of airborne bombing radar equipments produced by the Western Electric 

 Company during World War II. The third IF amplifier design illustrated 

 was developed somewhat later in the radar program for specific application 

 to the AN/APS-4 light-weight airborne search and interception radar equip- 

 ment. This amplifier employs 6AK5 tubes with synchronous single-tuned 

 interstage coupling networks realizing an over-all gain of 100 db for a band 

 width of 2 mc. The power consumption here is 14.5 watts and the weight 

 has been reduced to 9 ounces. This amplifier design has been employed in 

 a number of airborne radar equipments during the later period of the 

 past war. 



Fig. 31. — IF amplifier design as employed in AN/APS-4 airborne radar equipment. 



Figure 31 illustrates further mechanical constructional details of the 6AK5 

 amplifier described above, and the schematic circuit arrangement is given 

 in Fig. 32. Five stages of amplification and a second detector of a modified 

 plate circuit type is included. A positive polarity video output is obtained 

 from the cathode of the second detector and a single-section video low-pass 

 filter attenuates the IF signal which appears at the detector output. A 

 variable gain control voltage is applied to the plate circuits of the first three 

 stages of the amplifier. 



The mechanical arrangement of the components of this amplifier has been 

 devised with a view to achieving optimum frequency and gain stability. 



