546 



BELL SYSTEM TECHNICAL JOURNAL 



ured values to give the absolute values of envelope delay shown on the 

 curves are obtained from an approximate estimate of the delay of the 

 system under consideration. 



500 



1000 1500 



CYCLES PER SECOND 



2000 



2500 



Fig. 12 — Envelope delay characteristic for 708 miles of 16-ga. B-22-N two-wire circuit. 



No data are given here to show the results of measurements by the 

 method of Fig. 1. This circuit is particularly useful in the measure- 

 ment of networks and many examples of data obtained in this way are 

 included in another paper.'' 



Fig. 9 shows the results of impedance measurements made as shown 

 in Fig. 2 on a phase correcting network which was designed to equalize 

 the delay for 200 miles of 19-gauge H-174 side circuit for picture trans- 



