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IP 3-VOLTAGE RATIO READINGS
+
740
MENT REQUIRED:
RF V o l t m e t e r ( S i m i l i a r t o R o o n t o n M o d e l 91-CA
o r
M i l l i v a c T y p e MV-18
C ) .
S i g n a l o n r e c e i v e r f r e q u e n c y ( b e l o w s a t u r a t i o n ) .
C o r r e c t f r e q u e n c y c a n b e d e t e r m i n e d b y z e r o i n g
t h e d i s c r i m i n a t o r .
U s e 1 , 0 0 0 H e r t z s i g n a l w i t h
3 . 3
kHz d e v i a t i o n f o r a u d i o s t a g e .
DURE
A p p l y p r o b e s t o i n p u t o f s t a g e a n d s y s t e m n e g a -
t l v e ( - 1 0
VDC).
T a k e v o l t a g e r e a d i n g ( E l ) .
Move p r o b e s t o i n p u t o f f o l l o w i n g s t a g e a n d
s y s t e m n e g a t i v e .
T a k e r e a d i n g
( E Z ) .
C o n v e r t r e a d i n g s b y m e a n s o f
t h c l o l l o w i n g l o r -
muln:
E 2
V o l a t g e R a t i o
=
-
1
C h e c k r e s u l t s w i t h t y p i c a l v o l t a g e r a t i o s s h o w n
o n d i a g r a m .
RF AMP
IST MIXER
Q I
QI
J 4 4 1
A N T
IST OSC
IST MULT(X4)
MULT (X3)
Q
2
Q
I
2 4 4 4
t~
N T
x r n L
OP C O M
F R E O -
OPER F R E U - I 2 4 M H Z
2 4
J 4 4 2 - 4
-
L2
-
STEP 2A-SIMPLIFIED VTVM GAIN CHE(
HELICAL
RESONATOPS
L 4 4
-
L423
L 4 l O
L412
-
a1
OR
C O M
-
EQUI PhlENT REQUI RE11 :
L?"
L 4 l 3
-
L5
-
-
2 .
Signal
G e n e r a t o r ( m e a s u r e m e n t s h1560 o r e q u i v . )
PRELIhlINARY STEPS :
-
1 .
S e t VOLUME c o n t r o l f o r 4 . 1 8 v o l t s a c r o s s 3 . 5 - o h m
l o a d .
I f t h i s c a n n o t b e o b t a l n c d , s e t t o a p p r o x .
70'5 o i m a x .
rotation.
2 .
S e t SQUELCH c o n t r o l f u l l y r o u n t c r c l o c k w i s e .
-
T l i i ?
-
3 .
R c c e l v e r s h o u l d b e p r o p e r l y a l i g n e d .
-
T3/T4
4 .
C o n n e c t VTVM h e t w c e n s y s t e m n e g a t i v e a n d p o i n t s
i n d i c a t e d b y a r r o w ( e x c e p t f o r 1st MULT w h i c h
r e f e r e n c e s c h a s s i s g r o u n d ) .
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