THE RADAR RECEIVER 



785 



assure adequate deflection voltage or current for display purposes. The 

 sweep amplilier for range deflection purposes is essentially a specialized form 

 of video amplifier which must be capable of wide band transmission to ade- 

 quately reproduce the short time sweep wave forms and whose output char- 

 acteristics are such as to properly supply the high voltage or current signals 

 as required by the radar display system. Two general sweep amplifier de- 

 sign problems are presented for the two basic radar indicator types. The 



!+B 



Fig. 54. — -Range sweep anii)lilier circuit schematics for electrostatic-type radar displays. 



electrostatic type cathode-ray tube generally requires a balanced to ground 

 deflection signal of moderately high amplitude while the magnetic type cath- 

 ode-ray tube requires a large deflection current for its operation. 



Figure 51a illustrates a simplified schematic of a range sweep deflection 

 amplifier to be employed with an electrostatic type-A radar display. Here 

 the previously generated sweep wave form is impressed upon the grid of 

 Fi and after amplification a portion of the signal of opposite polarity and of 

 amplitude comparable with the input signal at the grid of Vi is applied to 

 the grid of Fo . The plate circuit of each tube is connected directly to the 

 deflection plate of the electrostatic cathode-ray tube. In this instance, 



