GAS-DISCHARGE TRANSMIT-RECEIVE SWITCH 



63 



condition existing at the beginning of each pulse. Normal leakage power 

 can be thought of as due to the finite voltage drop across the gas discharge 

 while the direct coupling is that component of the leakage power which 

 would be present if the voltage drop across the discharge were zero. 



"'O 05 10 15 20 25 



LOW LEVEL TRANSMISSION LOSS IN DB (=10LOG,q^) 



Fig. 16 — The variation in gas discharge power with the low level loss adjustment 



-SPIKE 



PULSE 

 LENGTH 



_ DIRECT 

 COUPLING 



PULSE AS DISPLAYED ON CRO 

 WITH WIDE-BAND AMPLIFIER 



IDEALIZED PULSE 

 FOR COMPUTATION 



Fig. 17 — The shape of the leakage power pulse 



The Spike. Because of the rapid rate of rise and fall of the spike, the 

 observable deflection on an oscilloscope is dependent upon the bandwidth 

 of the video amplifier and upon the energy in the spike. Although an 



