412 



The factor 



(22) 



BELL SYSTEM TECHNICAL JOURNAL 



-,[1 - (1 +7'')6'-"^] 



hrf 



approaches unity as w approaches zero, and Zio then agrees with the 



5 6 



VALUES OF r-' 



¥\g. 1 — Real and imaginary parts of the complex factor, 

 2 



(7^)- 



,[!-(!+ yr)e-^'\ 



plotted as functions of r' = |t''I = (47rXw)''-r. 



