SELF-TIMING REGENERATIVE REPEATERS 



915 



resonant circuits, the permissible deviations are as follows: 



This assumes that there are no random timing deviations and that the 

 tolerance to noise is reduced by not more than 2 db. 



0.2 Timing from Regenerated Pulse Train 



It will again be assumed that there are no random timing deviations. 

 Without a phase shift in the resonant circuit, let the regenerated pulses 

 be triggered at a time to . When there is a phase shift \f/', the pulses will 

 be triggered at a time ^o'. The timing wave derived from the regenerated 

 pulses will then have a time shift 



A = t,' - to^-^ rP'. 



This time shift will cause pulses to be regenerated with a time shift 

 /3'A, which must equal ^n' — ^o • Accordingly, 



U>' - to = ^' (to - to +^'/''), 



and 



to 



to = 



T /SV 



2x 1 - /3'" 



(5.3) 



With timing from the received pulse train with a phase shift ^ in the 

 resonant circuit, the following relation applies: 



to 



T 



to = — W- 



(5.4) 



If to — to is to be the same in both cases, so that the timing wave and 

 tolerance to noise is the same, the following relation must exist between 

 the phase shifts in the resonant circuit: 



,A' = ^(1 - 0') I 



(5.5) 



In this expression, (3 and (3' are the factors shown in Fig. 4. It will be 

 recognized from (5.5) that the smallest permissible phase shifts are ob- 

 tained for large values of /3'. From Fig. 4, it is seen that the largest 



