452 BEU^ SVSrnM TECHNICAL JOURNAL 



smooth liiii'.' Tliis is a good approximation over about tlie lower 

 half or two-thirds of the transmitting band; but to be adequate in the 

 upper part of the transmitting band it requires some modification in 

 its proportioning or even in its form, according to several circum- 

 stances, such as the relative termination, the amount and distribu- 

 tion of the dissipation, and the ratio of the highest contemplated 

 frequency to the critical frequency. The immediate neighborhood 

 of the critical fretiticncy is here disregarded, as ha\ing thus far been 

 unimportant in practice; modification of the networks to extend their 

 range of simulation right up to the critical frequency appears to 

 present much greater difficulties. 



PART Mil 

 Applic.xtions oi' the Simcl.\tin(; and the Compens.xting 



NeTWORIvS 



In this Part a considerable number of applications of the above- 

 described networks will be outlined. (For some details and further 

 ai)plications, reference may be made to the patents cited in Part V — 

 namely, Patent No. 1124904, No. 1167(593, and No. 1437422, per- 

 taining to the simulating networks; and No. 1243006 and No. 147.5997 

 I)ertaining to the compensating networks.) 



A jiplitations of the Simulating Networks 



Foremost of the uses of the simulating networks is their emjiloy- 

 ment for balancing purposes in connection with 22-type repealers, 

 already spoken of in the Introduction. 



.Another application of a simulating network is for terminating an 

 acltial ioadiii iiiu- in ijic luld or an artificial loaded line in the labora- 

 i()r\' in sucli a \\a\ as lo a\()id reflection effects. For this purpose 

 the proper terminating impedance is e\idently one e(iuai to the 

 complementary characteristic im[)edance of the loaded line. .Such a 

 terminating impedance is often needed in the making of electrical 

 tests or electrical measurements on a loatled line. 



l'"iirthermore, in making certain tests on apparatus normally as- 

 sociated with a hiadefl line, stich line may be represented conveniently 

 !)%■ the ;i|)pr(i|)ii.iic >iiun].itiiig network. 



A/'pliidlioiis of the Cotiipriisdtiitg Ncl'uvrks 



The compensating networks ha\e a wide \ariety of uses as neutral- 

 izing networks and also as simulating networks. These uses depend 



