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ADJUSTMENT
22
(e)
C o r r e c t i o n o f C a t h o d e R a y T u b e P o s i t i o n f o r T i l t (see F i g . 1 5 )
L o o s e n t h e s c r e w ( A ) h o l d i n g t h e C R T m o u n t i n g p l a t e a t t h e r e a r .
P l a c e t h e o s c i l l o s c o p e o n t h e n o r m a l o p e r a t i n g p o s i t i o n .
P u t t h e b l a d e o f a s c r e w d r i v e r in t h e s l i t ( B ) t o t u r n t h e C R T m o u n t i n g p l a t e f o r s e t t i n g t h e b r i g h t
l i n e c o r r e c t l y a g a i n s t t h e s c a l e g r a d u a t i o n .
C a r e f u l l y t i g h t e n t h e s c r e w ( A ) o b s e r v i n g t h a t t h e h o r i z o n t a l b r i g h t l i n e is n o t d e v i a t e d .
Ideal w a v e f o r m
W a v e f o r m for large t r i m m e r c a p a c i t o r
O v e r s h o o t (%) = b / a x 1 0 0
W a v e f o r m f o r s m a l l t r i m m e r c a p a c i t o r
V e r t i c a l f r e q u e n c y response at h i g h - f r e q u e n c i e s
( F o r e x a m p l e , it b e c o m e s 9 0 0 k H z - 3 d B . )
Fig, 14 Square wave characteristic adjustment by trimmer capacitor
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