DISTORTION CORRECTION 



487 



This then gave 



Ml = 2.8015-10-4; Ms = - 1.3929-10-12; TVs = - 2.4671 -10-«. 



Whence 



ai = 1.8846-10-4; a/ = .9169-10-4; h' = .7391 -10-«. 



These gave as the elements of the high-frequency phase corrector of 

 Fig. 16 



Li = 35.99 mh.; Co = .04999 mf.; 



Ls = 17.51 mh.; d = .02432 mf.; 



a = .02138 mf.; U = 15.40 mh. 



The small attenuation effects of coil dissipation were not included in 

 this design and they were later found to be negligible. An equivalent 

 network, namely, Network 15, Appendix IV, might have been used 

 instead of Network 16 for this phase corrector. But since it gives 

 less uniform or practical magnitudes for the inductances and capacities, 

 it would not be the simplest network to construct. 



dttenuabion Equalv^er 

 Hh^^ 



Phase Corredor 



Fig. 17 — Weather change distortion correcting networks for television circuit. 



(One step.) 



To provide for wet weather effects on the open-wire part of the 

 circuit, three identical weather change networks were designed each 

 of which was capable of correcting one half the increase in circuit dis- 

 tortion caused by a change from dry weather to average-wet weather. 

 With 0, 1, 2, or 3 of these supplementary networks added in tandem 

 to the dry weather network, provision was thus made for a total of 

 four assumed weather conditions which for convenience I have desig- 

 nated dry, semi-wet, wet, and extra-wet weather. These conditions 

 differed by small equal steps and their number was later found to be 

 32 



