PROGRAM TRAXS.MISSIOA CIRC CITS 249 



which cannot be entirely eliminated in design are reduced by the use of 

 delay equalizers along the circuits when they are set up. 



Conclusion 



From this discussion it is seen tliat the program networks are comprised 

 of many parts, each of which must nieet exacting requirements in order 

 that over-all results will be satisfactory. It is seen that equally important 

 with transmission are the requirements for plant flexibility, adequate 

 reserves, uniform practices, and centralized supervision of the networks. 



The features discussed have been those found desirable for present-day 

 network service. As indicated earlier, consideration of the needs of the 

 future as well as those of the present is an essential feature of the design 

 and engineering of the plant for program-network service. As a result 

 of having done this it will be possible to provide with present plant, and 

 with new plant currently being installed, adequate network facilities as 

 the broadcasting art develops toward higher standards of performance. 

 With the past experience as a guide, it appears that there should be no 

 fundamental difficulty in meeting all reasonable requiremients, always 

 remembering that in the long run, requirements and costs bear definite 

 relations to each other. 



Acknowledgment 



The authors of this paper gratefully acknowledge the assistance in 

 its preparation of many of their associates, especially Mr. W. E. Bloecker, 

 Mr. D. K. Gannett, and Mr. G. S. Bibbins. 



References 



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