C I R C U I T D E S C R I P T I O N
1. Receiver System
1) Receiver Signal Circuit
w
D7, D8
VHF
T h e r e c e i v e r s i g n a l f r o m t h e a n t e n n a i s p a s s e d t h r o u g h t h e d u p l e x e r , t h e c i r c u i t
c o n s i s t i n g o f V H F :
L o w - p a s s f i l t e r a n d U H F : h i g h - p a s s f i l t e r , a n d t h e s i g n a l i s
d i v i d e d i n t o V H F a n d U H F .
0 6
A N T
R F
s w
A M P
UHF
D303, D304
Q310
FL1
45 5k H z
A N T
_ J
R F
R F
S W
*
A M P
A M P
144M Band Receiver Circuit
T h e r e c e i v e r s i g n a l p a s s e d t h r o u g h t h e d u p l e x e r i s l e d t o t h e a n t e n n a s w i t c h ( D 7 ,
D 8 ) .
A f t e r p a s s i n g t h r o u g h t h e h i g h - p a s s f i l t e r , t h e s i g n a l i s a m p l i f i e d b y R F
a m p l i f i e r , . Q 6 . T h e a m p l i f i e d s i g n a l i s a m p l i f i e d a g a i n b y R F a m p l i f i e r Q 7 , t h e n t h e
u n w a n t e d s i g n a l w i l l b e e l i m i n a t e d b y t h e v a r i c a p t u n e d t r i p l e b a n d - p a s s f i l t e r .
S e c o n d l y t h e s i g n a l i s m i x e d w i t h t h e s i g n a l f r o m t h e f i r s t l o c a l o s c i l l a t o r i n t h e f i r s t
m i x e r Q 8 , t h e n c o n v e r t e d i n t o t h e f i r s t I F .
I t s u n w a n t e d s i g n a l i s a t t e n u a t e d i n t h e
c r y s t a l f i l t e r c i r c u i t . A f t e r a m p l i f i e d b y I F a m p l i f i e r Q 2 5 , t h e s i g n a l i s l e d t o I C 2
P i n 2 4 .
T h e s i g n a l i s m i x e d w i t h t h e s i g n a i f r o m t h e s e c o n d i o c a i o s c i l l a t o r i n I C 2 , t h e n
c o n v e r t e d i n t o t h e s e c o n d I F , a n d o u t p u t f r o m P i n 3 . T h e o u t p u t s i g n a l i s i n p u t t o
t h e I C 2 P i n 7 a g a i n a f t e r u n w a n t e d s i g n a l i s a t t e n u a t e d b y t h e c e r a m i c f i l t e r .
T h e
s i g n a l i s l e d t o t h e l i m i t e r a m p l i f i e r I C 2 , a n d d e m o d u l a t e d b y q u a d r a t u r e c i r c u i t i n
I C 2 , t h e n t h e s i g n a l i s o u t p u t f r o m P i n 1 2 a s t h e A F s i g n a l .
AIR Band Receiver Circuit
T h e r e c e i v e r s i g n a l p a s s e d t h r o u g h t h e d u p l e x e r i s l e d t o t h e a n t e n n a s w i t c h ( D 7 ,
D 8 ) .
A f t e r p a s s i n g t h r o u g h t h e h i g h - p a s s f i l t e r , t h e s i g n a l i s a m p l i f i e d b y R F
a m p l i f i e r Q 6 .
T h e a m p l i f i e d s i g n a l i s l e d t o t h e b a n d - p a s s f i l t e r i n A I R F r o n t U n i t ,
a n d a m p l i f i e d b y R F a m p l i f i e r Q 9 0 1 , t h e n o u t p u t f r o m P i n 9 .
S e c o n d l y t h e s i g n a l i s m i x e d w i t h t h e s i g n a l f r o m t h e f i r s t l o c a l o s c i l l a t o r i n t h e f i r s t
3
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Содержание DR-610E
Страница 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...
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Страница 37: ...E X P L O D E D V IE W A P 0017 2 L C D V ie w 35 All manuals and user guides at all guides com...
Страница 38: ...FM0076 All manuals and user guides at all guides com...
Страница 39: ...0 0 0 UE0116 All manuals and user guides at all guides com...
Страница 60: ...P 0 0 All manuals and user guides at all guides com...
Страница 64: ...Main Unit 9600bps SP OUT 51 All manuals and user guides at all guides com...
Страница 69: ...P C B O A R D V IE W 1 V H F M A IN A IR U n it S id e A All manuals and user guides at all guides com...
Страница 77: ...a 2 CPU B lock D i a g r a m All manuals and user guides at all guides com...
Страница 79: ...S C H E M A T IC D IA G R A M 1 V H F M A IN U N IT All manuals and user guides at all guides com...
Страница 80: ...2 U H F M A IN U N IT All manuals and user guides at all guides com...
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Страница 83: ...V j Ni VHF VCO UNIT All manuals and user guides at all guides com...
Страница 84: ...C O UHF PLL UNIT All manuals and user guides at all guides com...
Страница 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...
Страница 87: ...VI O l M R DTMF All manuals and user guides at all guides com...
Страница 88: ...9 E H M 3 9 oo m n o cri O C 5 All manuals and user guides at all guides com...