Synchronization System for Two-Way Television

E L E V I S I O N transmission requires n o t only synchronization o f the t r a n s m i t t i n g a n d receiving e q u i p m e n t b u t such s y n c h r o n i z a t i o n m u s t be held to a narrow phase angle so t h a t the scanning discs at the t r a n s m i t t i n g a n d receiving end will never depart more t h a n a small fracIn t h e 1927 tion of a picture f r a m e w i d t h from the desired position. 1 s u p p l e m e n t a r y D . C . motors t o facilitate starting. ficient power to the synchronous motors.