5) DTMF Encoder Circuit
D T M F e n c o d e r I C 6 0 2 g e n e r a t e s t h e a u d i o s i n e w a v e ( b a s e d o n t h e 4 - b i t d a t a f r o m
I C 6 0 1 ) , a n d s y n t h e s i z e s t h e s i g n a l w h i c h i s a p p l i e d f o r t h e D T M F d i a l i n g a n d
o u t p u t s t h e s i g n a l f r o m P i n 1 4 .
A f t e r t h e l e v e l o f D T M F s i g n a l i s a d j u s t e d b y t h e v a r i a b l e r e g i s t e r V R 6 0 2 , a m p l i
f i e d b y I C 6 0 8 .
T h e a m p l i f i e d s i g n a l i s a d d e d t o e a c h v a r i c a p o f V C O f o r m o d u l a
t i o n .
A t t h e s a m e t i m e t h e m o n i t o r s o u n d i s p a s s e d t h r o u g h t h e A F c i r c u i t , a n d
o u t p u t f r o m t h e s p e a k e r .
6) Cross Band Repeater Circuit
I n t h e C r o s s B a n d R e p e a t e r M o d e , Q 6 Q 3 i n C r o s s B a n d M u t e C i r c u i t i s t u r n e d
O F F , a n d t h e A F s i g n a l i s c o n n e c t e d t o t h e M o d u l a t i o n C i r c u i t .
W h e n t h e s q u e l c h o f V H F i s o p e n e d , t h e A F s i g n a l R O V ( V H F ) i s u n m u t e d .
T h e n
a f t e r t h e l e v e l o f s i g n a l i s a d j u s t e d b y t h e v a r i a b l e r e g i s t e r V R 6 0 3 , i t i s a m p l i f i e d b y
I C 6 0 8 . T h e a m p l i f i e d m o d u l a t i o n s i g n a l i s a d d e d t o t h e v a r i c a p f o r t h e m o d u l a t i o n
o f U H F V C O , t h e n U H F e n t e r s i n t o t h e t r a n s m i t t i n g m o d e .
W h e n t h e s q u e l c h o f U H F i s o p e n e d , t h e A F s i g n a l R O U ( U H F ) i s u n m u t e d .
T h e n
a f t e r t h e l e v e l o f s i g n a l i s a d j u s t e d b y t h e v a r i a b l e r e g i s t e r V R 6 0 3 , i t i s a m p l i f i e d b y
I C 6 0 8 . T h e a m p l i f i e d m o d u l a t i o n s i g n a l i s a d d e d t o t h e v a r i c a p f o r t h e m o d u l a t i o n
o f V H F V C O , t h e n V H F e n t e r s i n t o t h e t r a n s m i t t i n g m o d e .
7) Tone Burst Output Circuit
W h i l e p r e s s i n g t h e T o n e B u r s t k e y , t h e s q u a r e p u l s e i s o u t p u t f r o m C P U I C 6 0 1 ,
P i n 2 7 ( 1 7 5 0 ) , t h e n t h e w a v e i s i n t e g r a t e d b y C R t o o b t a i n t h e s i n e w a v e .
A f t e r t h e
l e v e l o f t h e s i g n a l i s a d j u s t e d b y t h e v a r i a b l e r e g i s t e r V R 6 0 1 . T h e s i g n a l i s
a m p l i f i e d b y I C 6 0 8 .
T h e n i t i s a d d e d t o e a c h v a r i c a p f o r m o d u l a t i o n o f V C O .
6. CTCSS Tone Encoder Circuit
1) Reset Circuit
T h e C P U i s i n i t i a l i z e d b y s e t t i n g t h e R E S t e r m i n a l t o " L " f o r 1 0 m s e c o r m o r e
b e c a u s e t h e o s c i l l a t i o n o f t h e C P U i s u n s t a b l e j u s t a f t e r t h e p o w e r i s O N .
2) Tone Generating Circuit
T h e m i m i c s i n e w a v e i s o u t p u t f r o m I C 9 8 1 P i n 1 0 ~ 1 3 , a n d c o n v e r t e d t o t h e a n a
l o g u e w a v e b y t h e l a d d e r r e g i s t e r t o g e t 5 0 w a v e s w i t h i n 6 7 . 5 - 2 5 4 , 1 .
A f t e r a m p l i f i e d b y Q 9 8 1 , t h e t o n e s i g n a l i s o u t p u t t o T O U T t e r m i n a l .
13
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Summary of Contents for DR-610E
Page 32: ...f m 1 k H z T a 2 5 C ro o AF OUTPUT 0 0 1j j F All manuals and user guides at all guides com...
Page 35: ...All manuals and user guides at all guides com...
Page 38: ...FM0076 All manuals and user guides at all guides com...
Page 39: ...0 0 0 UE0116 All manuals and user guides at all guides com...
Page 60: ...P 0 0 All manuals and user guides at all guides com...
Page 64: ...Main Unit 9600bps SP OUT 51 All manuals and user guides at all guides com...
Page 77: ...a 2 CPU B lock D i a g r a m All manuals and user guides at all guides com...
Page 80: ...2 U H F M A IN U N IT All manuals and user guides at all guides com...
Page 81: ...All manuals and user guides at all guides com a l l g u i d e s c o m...
Page 82: ...All manuals and user guides at all guides com...
Page 83: ...V j Ni VHF VCO UNIT All manuals and user guides at all guides com...
Page 84: ...C O UHF PLL UNIT All manuals and user guides at all guides com...
Page 85: ...R 6 1 UHF VCO UNIT 6 UHF V C O PLL U N T All manuals and user guides at all guides com...
Page 87: ...VI O l M R DTMF All manuals and user guides at all guides com...
Page 88: ...9 E H M 3 9 oo m n o cri O C 5 All manuals and user guides at all guides com...