i.o.iDLXC I'OR -n-i./'rnoNii cih'(rrrs 



261 



rcquirenieiit prcxiousK' meiit ioiud, fixes the cut-olT characteristics and, 

 hence, the slope of the termination inii:)e(hince-freqnency characteristic. 

 These general considerations ha\e led to the standar(lizatif)n of the 

 £-28-10 loadint;- s\-steni for nse on entrance cable and inierniediatc 

 cable condnctors associated with non-loaded open wire lines, (ieneral 

 data for this system are given in Table XII, and the computed im- 

 pedance characteristics are illustrated in JMg. 14, wh.ich also gixes 



1000 



-400 L^ 

 



800 1600 2400 3200 

 FREQUENCY-CYCLES 



4000 



Fig. 14 — -Typical impedance-frequency characteristics of loaded and non-loaded 

 entrance cable and non-loaded open wire line 



the characteristic impedance curves for the non-loaded open wire line 

 and the non-loaded cable. Since the E-28-16 loading system is a low 

 impedance loading, the attenuation improvement is small relative 

 to that of other types of loading system which are primarily installed 

 for attenuation improvement. 



Table XII also gives general data regarding the M-44-2r) entrance 

 cable loading system which has been used to some extent as a sub- 

 stitute for the E-28-1G loading system on cables connected to non- 

 loaded open wire lines. The M-44-25 system used higher inductance 



