TRANSISTOR BINARY PULSE REGENERATOR 



1077 



(a) 



(b) 



Plate V — (a) with 1, repeater output; 2, jitter on output pulse; 3, sampling 

 pulse, (b) with 1, signal pulse at repeater input; 2, 672-kc timing pips; 3, interfer- 

 ence input. 



triggered by pulses of one polarity, the reversing switch permits the 

 independent measuring of different types of errors. The counter used 

 in this study has 9 decades capable of counting and recording (10^ — 1) 

 errors at 10^ counts per second. 



4.2 Discussion of Impulse Noise Generator 



A study of the noise in cable pairs leading from a central office indicate 

 that impulse noise will cause much of the expected interference on pulse 

 systems. In order to simulate the effect of this type of interference, a 

 generator was built which produces uniformly shaped pulses over a wide 

 range of rates. The polarity of these pulses can be reversed and their 

 amplitude varied continuously from zero to a value exceeding the 

 peaks of the signal pulses. These impulses were introduced into the 

 center of a transmission cable through a high impedance. Plate V(b) 

 shows photographs comparing the impulse with a signal pulse. The 

 repetition rate for the impulse interference used in this investigation 

 was lOVsec, which is low compared to the nominal pulse repetition rate 

 of the signal (6.72 X lOVsec). With the relatively large separation be- 

 tween interfering impulses, there is no measurable interaction between 

 errors produced in the repeater. At the same time the impulse rate is 

 high enough to get an excellent statistical distribution in the 10 second 

 interval used in these measurements. 



