PRIVATE LINE DATA TRANSMISSION 



1465 



Table II — Characterization of Telegraph Distortion and 

 AND Error Rates by Telegraph Transmission Coefficient 



A very brief summary of some of the experiments in the use of VF 

 telegraph over untreated N carrier is given in Table III. This portion 

 of the results covers Nl circuits with compandors which have slightly 

 more noise than the objective which is set for the telephone use of such 

 circuits. The noise was 28 dba at the zero transmission level point, as 

 against an objective of 26 dba at that point. It is noted in Section 3.3.2 

 that the measurement of noise in these terms is not altogether reliable 

 in the evaluation of its effects on transmission systems that use pulses. 

 Thus, these experiments must be considered as giving only a general 

 indication of the situation. 



Table III — Summary of Telegraph Peformance over Noisy 



N-I Carrier Link 



1. Number of channels. . 



2. Frequency space used . 



3. Words per minute .... 



4. Total bits per second. 



40C1 (AM) 



6 

 1020 

 75 

 342 



43 Al (FS) 



75 



684 



12 

 2040 cycles 



100 

 888 



