IST MIXER
QI
HI I F AMP
Q
I
L---x3
* L - _
I
C.
361
I 2ND MIXER
I
Q 2
I
I
IST LO
IF
1
2ND LO IF
I
AMP
I
AMP
I
03
I
QI
I
I
1
H C L ~ C A L
TZ
-
RESOhATORS
L414
-
L423
2 5 M V
INJECTION
VOLTAGE
MULT (X3)
MULT(X2)
2ND OSC
Q 1
Q2
Q4
T31T4
L 4 2 4
X READING TAKEV WITH BASE OF ZND
OSC
SHORTED TO SYSTEM
hlEGITlVE
X X REMOVE SHORT ON 2ND OSC 8 INCREASE
INPUT SIGNAL LEVEL TO 4PPRDX
I M V
, 4 4 2 - 1
TO OVERHIDE INJECTION VOLTAGE
\
\
' - x .
=IED VTVM GAIN CHECKS
- - ~
. -
- .
~-
.
~.
-~
SIGNAL GLNEWATOR
INPUT AT
J 4 4 1
MAINTAIN
SETTING AT
UNMODULATEO
UNMODUL ATED
UNMODULATED
UUMODULPiT
DISCRIMINATOR ZERO
I N C H E l S E GENERATOR
lNCREASE SIGNAL
INCREASE SIGNAL
INCREASE SlGl
PROCEDURE
OUTPUT U N T I L VTVM
GENERATOR OUTPUT
GENERATOR OUTPUT
GENERAT09 0 L
READING
ON 1.5 V
FROM ZERO UNTIL
FROM ZERO U N T I L
FROM ZERO U
SCALE DECREASES
V T V M READING DE-
VTVM READING DE-
VTVM READIN
5y
5~ MV
CREASES BY
5 %
CREASES BY
5 %
CREASES B Y
0.8
VDC
0.25
VDC
GENERATOR OUTPUT
G E ~ E R A T O R
OUTPUT
GENERATOR OUTPUT
GENERATOR
OL
SHOULD
BE
aPPRoX
SWLD
BE
n P P R o x
SHOULD
BE
APPROX
SHOULD
BE
A F
READING
20
MILLIVOLTS
600
MICROVOLTS
5
MICROVOLTS
0.3
MICRDVOI
. s u r e m e n t s
Tr1560
o r e q u i v . )
r 4 . 1 8 v o l t s a c r o s s
3.5-ohm
be o b t a i n e d , s e t t o a p p r o x
u l l y c o u n t e r c l o c k w i s e .
o p e r l y a l i g n e d .
s y s t e m
n c x a t i v e
and p o i n t s
K c e p t f o r
1st
MULT
w h i c h
3und).
STEP 26-AUDIO & SQUELCH WAVEFO1
EQUIPMENT REQUIRED:
1.
O s c i l l o s c o p e .
2 .
S i g n a l g e n e r a t o r ( m e a s u r e m e n t s M560 t o e q u i v a l e
PRELIMINARY 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
l o a d .
I f t h i s c a n n o t b e o b t a i n e d ,
s e t t o a p p r c
70% o f
max.
rotation.
2 .
S e t SQUELCH c o n t r o l f u l l y c o u n t e r c l o c k w i s e .
3 .
R e c e i v e r s h o u l d be p r o p e r l y a l i g n e d .
4 .
C o n n e c t o s c i l l o s c o p e b e t w e e n s y s t e m n e g a t i v e a r
p o i n t s i n d i c a t e d b y a r r o w .
