EXPERIMENTAL TRAXSVERSAL EQUALIZER FOR TD-2 



1431 



tioiis of delay slope equalizers. The characteristics of the 319A, B and C 

 equalizers provided for this purpose are shown in Fig. 2. Each equalizer 

 consists of two bridged-T all-pass sections. There is also some variation 

 in bandwidth of the TD-2 repeaters, resulting in part from the fact that 

 the waveguide filters used in the higher frequency radio channels are 

 somewhat broader than those in the lower frequency channels. This 

 ^'ariation in bandwidth results in delay distortion which has a parabolic 

 shape with frequency. Use of a larger or smaller number of the basic 

 315A ec^ualizers corrects this. 



Over long circuits, small distortions in the gain shape of the TD-2 



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 FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 2 — Delaj- characteristics of 319 type equalizers. Combinations of these 

 are used at main stations to equalize delay slope of the system. 



