1.4 



" 1.2 



0.4 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 



FREQUENCY IN KILOCYCLES PER SECOND 



Fig. 5 — Attenuation of open-wire pairs, 165-miI copper, 8-inch spacing, CS insulators. 



z 12 



20 



40 50 60 70 80 90 100 110 

 FREQUENCY IN KILOCYCLES PER SECOND 



120 130 140 150 



Fig. 6 — Attenuation of 165-mil copper, 8-inch spaced pair of wires measured on a 

 105-mJle section of the Amarillo-Albuquerque line in clear weather. 



