5.11 Cone Centering Check - Tandy 6000 Service Manual

5.11 CONE CENTERING CHECK

Cone c e n te r in g is th e a b ili t y o f th e cone c la m p ­
in g m e c h a n is m to c e n te r th e d is k e tte on th e
h u b c a u s in g i t to r o ta te c o n c e n tr ic a lly . T h is
c h e c k s h o u ld be m a d e w h e n e v e r th e cone le v e r
a s s e m b ly h a s been re m o v e d o r re p la c e d . I f
cone c e n te rin g c a n n o t be a c h ie v e d , v e r if y th e
m e a s u re m e n t w it h a second d is k e tte . O th e r ­
w is e r e fe r to th e tro u b le s h o o tin g g u id e .
1. S e t u p th e oscillo sco p e to r e a d :
C h a n n e l A : U 2 , P in 14
C h a n n e l B : U 2 , P in 15
V e r t ic a l A m p lit u d e : 50 m illiv o lt s p e r
G ro u n d : T e s t P o in t 8
R ead D if f e r e n t ia lly : A a n d B , B
T im e B a se: 10 m ic ro se co n d s p e r
d iv is io n
E x t e r n a l T r ig g e r : T e s t P o in t 10,
d iv is io n
in v e r te d
p o s itiv e edge
2. A p p ly p o w e r to th e d riv e .
3. S e le c t th e d r iv e .
4. Seek to T r a c k 0.
5. W r ite a 2 F p a tte r n on H e a d 0.
6. M e a s u re th e a m p litu d e o f th e s ig n a l b y
p o s itio n in g
s ig n a l on th e c e n te r v e r t ic a l g r a tic u le .
7. R elease th e f r o n t le v e r, a n d re m o v e th e
d is k e tte .
8. R e in s e rt th e d is k e tte , a n d close th e
f r o n t le v e r.
9. R e p e a t S teps 7 a n d 8 u n t i l th e dee pe st
d ip in th e w a v e fo rm is p ro d u ce d .
10. M e a s u re th e a m p litu d e o f th e deepest
d ip .
11. D iv id e th is m e a s u re m e n t b y th e m e a ­
s u re m e n t in S tep 6, a n d m u lt ip ly i t b y
100. T h is r e s u lt s h o u ld be a bove 85
p e rc e n t.
12. T h e s ig n a l a m p litu d e s h o u ld n o t de ­
crease b e lo w 85 p e rc e n t o f th e a v e ra g e
a m p litu d e a t a n y p o in t o n th e tr a c k .
5-12
th e deepe st d ip in th e