PRODUCTION OF TELEVISION SIGNALS 



581 



in the slightly better definition of sharp narrow lines such as the 

 frames of horn-rimmed spectacles. When a system of considerable 

 attenuation is employed between the sending and receiving terminals, 

 it would in general be preferable to split the equalizing between the 

 sending and receiving ends to make the best use of the sending end 

 power in riding over interference. 



28 



24 



20 



16 



12- 



-Q|3 



-8 



APERTURE EQUALIZER CHARACTERISTICS 



Fig. 18 — Circuit for equalizing the aperture effect and its amplitude and 

 phase characteristics 



In arriving at the amount of electrical equalization which shall be 

 adopted in any particular case it must of course be borne in mind 

 that as the aperture is made narrower the amount of distortion intro- 

 duced by it becomes less. As we narrow the aperture, however, the 

 available illumination becomes less and the signal generated by the 

 photoelectric cell becomes smaller. A limit is therefore soon reached 

 at which the difficulties of amplification become greater than the 



