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DESCRIPTION
G e n e r a l E l e c t r i c MASTR P r o g r e s s L i n e
R e c e i v e r s Types ER-42-E
&
G a r e double-con-
v e r s i o n , s u p e r h e t e r o d y n e F M r e c e i v e r s de-
s i g n e d f o r o p e r a t i o n f n t h e 406-420 and 450-
470 m e g a h e r t z b a n d s .
The Type ER-42-E
Re-
c e i v e r s c o n t a i n a s t a n d a r d o s c i l l a t o r w i t h
a f r e q u e n c y s t a b i l i t y of *.0005%,
w h i l e t h e
Type ER-42-G
R e c e i v e r s c o n t a i n a n I n t e g r a t e d
C i r c u i t O s c i l l a t o r Module (ICOM) w i t h a f r e -
quency s t a b i l i t y of f 0 . 0 0 0 2 % .
S t a n d a r d and
u l t r a - h i g h
s e n s i t i v i t y (UHS) v e r s i o n s a r e
a v a i l a b l e f o r b o t h t y p e s .
The r e c e i v e r s a r e of s i n g l e - u n i t con-
s t r u c t i o n and a r e c o m p l e t e l y housed i n an
aluminum c a s t i n g f o r maximum s h i e l d i n g and
r i g i d i t y .
The t o p p a r t o f t h e c a s t i n g con-
t a i n s t h e f r o n t e n d t h r o u g h t h e 1st low I F
a m p l i f i e r s t a g e s .
The bottom p o r t i o n of t h e
c a s t i n g c o n t a i n s t h e a u d i o s q u e l c h b o a r d and
t h e o p t i o n a l Channel Guard e n c o d e r - d e c o d e r
b o a r d .
CIRCUIT ANALYSIS
The MASTR P r o g r e s s L i n e R e c e i v e r
is
c o m p l e t e l y t r a n s i s t o r i z e d , u s i n g s i l i c o n
t r a n s i s t o r s t h r o u g h o u t f o r added r e l i a b i l i t y .
I n p u t l e a d s t o t h e r e c e i v e r a r e i n d i v i d u a l l y
f i l t e r e d by t h e 20-pin f e e d - t h r o u g h by-pass
c o n n e c t o r 5443.
A r e g u l a t e d +10 v o l t s is
u s e d f o r a l l r e c e i v e r s t a g e s e x c e p t t h e
a u d i o PA s t a g e which o p e r a t e s from t h e 12-
v o l t s y s t e m s u p p l y .
C e n t r a l i z e d m e t e r i n g j a c k 5442 is p r o -
v i d e d f o r u s e w i t h G e n e r a l E l e c t r i c T e s t
S e t Models 4EX3A10 o r 4EXBKl1, f o r e a s e of
a l i g n m e n t and s e r v i c i n g .
The T e s t S e t m e t e r s
t h e o s c i l l a t o r , m u l t i p l i e r , and l i m i t e r
s t a g e s a s w e l l a s t h e d i s c r i m i n a t o r , and
r e g u l a t e d 1 0 v o l t s .
RF AMPLIFIER (A410/A411)
RF
A m p l i f i e r A410/A411 is u s e d o n l y i n
u l t r a - h i g h s e n s i t i v i t y (UHS) r e c e i v e r s and
c o n s i s t s of two t u n e d h e l i c a l r e s o n a t o r s
and a n RF a m p l i f i e r (Ql)
.
The RF a m p l i f i e r u s e s a F i e l d - E f f e c t
T r a n s i s t o r (FET) a s t h e a c t i v e d e v i c e .
A
FET may be c o n s i d e r e d a s e m i c o n d u c t o r c u r -
r e n t p a t h ( o r c h a n n e l ) whose r e s i s t a n c e is
v a r i e d by a v o l t a g e a p p l i e d between t h e
" g a t e " and " s o u r c e " t e r m i n a l s .
Lead i d e n t -
i f i c a t i o n f o r t h e FET is shown i n F i g u r e 2A.
The FET h a s v o l t a g e - c o n t r o l l e d c h a r a c t e r i s -
t i c s , and may be compared t o a vacuum t u b e
i n o p e r a t i o n ( s e e F i g u r e 2B).
L - -
4 0 6 - 4 X I NHZ
4 1 0 4 1 0 YHZ
7
I2 l
I S T MIXER
- - -
XTAL
OR
ICON RANGE
4 5 0 - 4 7 0 N W Z 1 8 . 2 3 3 3 3 3
-
19.066 6 6 NHZ
4 0 6 - 4 2 0 Y W l - 16.401 I1
-
1 6 . 9 8 3 3 3 3 KHz
\
/
1 4 2 8 i A 4 2 9
J
- -
CHANNEL GUARD
-
y
XTAL
OR ICOM FREQ
.
OPER
FREO
-
I2
4
Y H Z
1 4 0 6 - 4 7 0 MU11
24
F i g u r e 1
-
R e c e i v e r Block Diagram
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