200 



BELL SYSTEM TECHNICAL JOURNAL 



20 30 40 50 60 70 80 100 200 300 400 



FREQUENCY IN CYCLES PER SECOND (ABOVE 68 KC) 



Fig. 4 — The sharpness of the upper cut-off of the filter is shown in this enlarged loss 

 characteristic. 



tfl 5 



o 



H 2 



Fif 



-7 -6 -5 -4 -3 -2 -1 



FREQUENCY IN KILOCYCLES PER SECOND (CARRIER) 



(FROM 88-KC CARRIER) 



-Dela_\' distortion in the pass band of the filter. 



and terminated at each end by half-sections of the constant-k ladder type. 

 The performance of the filter results almost entirely from the lattice sections 

 since they control the flatness of the pass band, the sharpness of the cut-of¥ 



