LOADED USES AND COMPENSATING NETWORKS 451 



the nominal iinpt-dancc and the critical frequency of the loaded line 

 without much affecting the relative impedance when expressed as a 

 function of the relative frequency, over the first transmitting band" 

 and the lower part of the succeeding attenuating hand. Thus an 

 approximate way of taking account of the effects of small distributed 

 inductance is to deal with the constants Lo' and Coof the corresponding 

 "principal simulative loaded line"; since this line has no distributed 

 inductance it is seen that the networks described in Part V for loaded 

 lines without distributed inductance are adequate for loaded lines 

 with small distributed inductance; the design-formulas remain un- 

 changed beyond substituting Lo' for L' and Co for C; however, the 

 simulative precision of the networks is altered slightly. 



A slightly better approximation may be secured by working not 

 only with Lo and Co but also with fictitious \alues of a and a', say 

 (To and at,', slighth- different from those which would be best if there 

 were no distributed inductance. 



Owing to the presence of a certain amount of distributed inductance 

 in all transmission lines (even in cables), simulation of the <r'-load 

 imjjedance (<t'><t»') by means of a fractional-load {at) type of basic 

 network built out to a'-load is slightly more precise than simulation 

 of the o--section impedance {<j = <t') by means of a fractional-section 

 (at,) type of basic network built out to (7-section. This is evident 

 from the latter pt>rtion of Part III of this paper. 



(Regarding the effects of small distributed inductance in loaded 

 lines. Patent No. 1167693 may be of some interest.) 



P.ART \II 

 Networks for Dissipative Lo.\ded Lines 



A natural first-approximation network for simulating the impedance 

 of a dissipative loaded line is the network for the corresponding non- 

 dissipative loaded line, the excess impedance thus being neglected; 

 in the case of a high grade loaded line this is a good approximation 

 except at ver>- low frequencies. \'arious forms and types of networks 

 for non-dissipati\e loaded lines having the basic relative terminations 

 were described in Parts \' and VI; those networks ("basic networks") 

 can be built-out readily to any relative terminations by means of 

 simple non-dissipative building-out structures. 



When the excess impedance of the loaded line is not negligible 

 an excess-simulator is required. A first-approximation excess- 

 simulator for a loaded line is the excess-simulator for the correspwnding 



