726 



BELL SYSTEM TECHNICAL JOURNAL 



oscillator all of which employ the GL-2C4() lighthouse tube. This particular 

 equipment example has been developed in the form of a sliding drawer to 

 assure ease of maintenance but with no sacrifice in rigidity of mechanical 

 assembly so necessary in this type of equipment. P'urther mechanical 

 details of the cavity and tube structures of each component are shown in 

 Fig. 21 and are generally similar to the examples previously described. 

 These cavity structures are heavily silver-plated to assure good electrical 

 and thermal conductivity. The problem of adequate conduction of heat 

 from the GL-2C40 vacuum tube under the severe ambient temperatures 



-142 



-ie6 



-170 



-146 -150 -154 -156 -162 

 D-C REPELLER POTENTIAL IN VOLTi 



Fig. 19. — Power output and frequency deviation vs. repeller voltage for 2K25-type re- 

 flex oscillator. 



encountered in military service is extremely important. Positive locking 

 devices are provided for all adjustments in this mechanical design. 



Figure 22 indicates the schematic diagram of this design. It may be 

 observed that separation filters arc employed extensively to assure negligible 

 interaction effects between the various stages through the common power 

 supply connections. 



The over-all performance of this {)articular design of a radar receiver 

 input circuit is as follows: 



Input rrcfjuency 1000 



Output Intermediate Frequency. 



Over-all \Va\m\ Width 



Over-all Ciain 



Over-all Noise Figure 



Injjut Impedance 



Output IF Impedance 



60 mc 

 5 mc 

 18(11) 

 14 dl) 

 -SO ohms 

 75 ohms 



