TRANSISTOR BINARY PULSE REGENERATOR 



1075 



60 

 55 

 50 

 45 

 40 

 35 

 30 

 25 

 20 

 15 

 10 

 5 

 



8 10 20 40 60 80 100 200 



FREQUENCY IN KILOCYCLES PER SECOND 



400 600 1000 



Fig. 6 — Effect of changing the length of 19 gauge line with fixed equalization. 



4.1 Description of Error Detecting and Counting Circuit 



An error detecting and counting circuit was built to count insertion 

 and omission errors. This circuit (block diagram, Fig. 7) is a coincidence 

 detector in which each pulse or space of the repeater input signal is 

 compared to its corresponding regenerated output. As long as the two 

 sources are the same, i.e., having corresponding pulses or spaces, there 

 is no output from the detector. If the two differ the detector produces 

 an output pulse which may be caused to actuate the counting circuit. 

 The code generator as has already been described produces a number of 

 different types of signal codes. 



The output of the code generator is transmitted over 0.56 miles of 

 equalized 32 gauge cable to the regenerative repeater under test. Inter- 

 ference is introduced at the repeater input when desired. A portion of 

 the code generator output is differentiated and passed over a delay 

 cable whose delay is substantially that of the section of 32 gauge line 

 over which the signal is transmitted. This delayed signal is regenerated 

 without error by the single shot blocking oscillator A, The width of the 

 blocking oscillator pulses are adjusted to be about half of the total 

 timing interval. The width of the pulses from the regenerative repeater 



