OPEN-WIRE CROSSTALK 



231 



for example, the phantom circuit composed of wires 1 and 2 as one 

 side and 5 and 6 as the other side. The method of estimating the 

 total effect of all possible tertiary circuits will be discussed later. 



0.1 0.2 0.3 0.4 0.5 I 2 3 4 5 10 



FREQUENCY IN KILOCYCLES PER SECOND 



Fig. 33 — Variation of direct crosstalk coefficients with frequency. 



The immediate problem is to compute the crosstalk currents In 

 circuit b at the ends of the length dx due to currents and charges in 

 circuit c in this length and caused by transmission over circuit a 

 through dx. 



The crosstalk currents in circuit b due to currents and charges in 

 circuit a were computed by determining the equivalent series and 

 shunt e.m.f.'s in circuit b. The effect of currents and charges in 

 circuit c on crosstalk currents in circuit b may be computed in a similar 

 manner. The series e.m.f. in circuit b proportional to the current in 



