BENDIX ADF-T12B Maintenance Manual page 27

M A I N T E N A N C E P R . V C T I C E S
D E T A I L S T E P S / W O R K I T E M S
K E Y I T E M S
Adjust the tuning cores of local oscillator
c o i l L I O , m i x e r c o i l L 7 a n d r - f c o i l L 4
(in this order), for maximum indication on
t u n i n g m e t e r .
(e) Adjust output of signal generator as
f o u n d n e c e s s a r y t o m a i n t a i n m i d - s c a l e
r e a d i n g o n t u n i n g m e t e r.
(f)
A d j u s t t h e s i g n a l g e n e r a t o r t o 4 0 0 k c .
u n m o d u l a t e d .
(g) Adjust the receiver tuning knob for a
frequency of 400 kc.
( h ) A d j u s t t r i m m e r c a p a c i t o r s C 3 9 , C 2 4 a n d
C22 (in this order), for maximum indication
on the tuning meter.
M a i n t a i n t u n i n g m e t e r a t m i d - s c a l e
i n d i c a t i o n d u r i n g a d j u s t m e n t s , a n d
repeat steps (b) through (h) until no
f u r t h e r i m p r o v e m e n t c a n b e o b t a i n o b ¬
t a i n e d .
In each case, always make the last ad¬
justment with the trimmer capacitor.
( i )
Repeat steps (b) through (h) as follows on
b a n d s 2 a n d 3 :
B a n d 2 : 5 0 0 k c - A d j u s t L l l , L 8 a n d L 5
8 0 0 k c - A d j u s t C 4 1 , C 2 6 a n d C 1 7
B a n d 3 : 1 0 0 0 k c - A d j u s t L 1 2 , L 9 a n d L 6
1 6 0 0 k c - A d j u s t C 4 3 , C 2 8 a n d C 1 9
(3) Loop Stage Alignment
( a ) S e t t h e r e c e i v e r f u n c t i o n s w i t c h t o t h e A D F
p o s i t i o n .
( b ) S e t t h e r e c e i v e r b a n d s e l e c t o r s w i t c h t o t h e
1 9 0 - 4 4 0 p o s i t i o n .
i
s
N O T E
Servo motor must not rotate while aligning loop stages.
Do not attempt to retard motor by holding or clamping.
The recommended method of stopping motor is as follows:
J l
J l
2
7
16
O '
S E R V O
A M P L I F I E R - I N D I C A T O R
A D F
R E C E I V E R
0
A C
0 . 6 8 9 . I K
V T V M
(During loop alignment, switch must be in position 1)
(c) Adjust the signal generator to 200 kc, un¬
m o d u l a t e d a n d f o r a fi e l d s t r e n g t h o f 2 0 0
m i c r o v o l t s - p e r - m e t e r .
Manually rotate fixed loop through 90
d e g r e e s .
(
A p r i l 1 9 6 5
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