IF SECTION
ALlGNMENT
Step 1: Conneet instruments
as
shown below.
3.8
-4.2V
p.p
T
+15kHz
SCOPE
TP·3
UNIT
UNDER
TEST
10.7
MHz
L-ilé----lSWEEP
GENERATOR
001uF
TP1
-15kHz
INPUT
100~JV
Step 2:
Adjust
T10
for
maximum
output
so
that
the
455
kHz marker is in the center of the discrimi-
nator
curve and
for
best linearity,
as
shown above.
During alignment, maintain Sweep Generator
output
at the lowest level possible
to
prevent
overloading.
VCO
ALlGNMENT
Step 3:
Step 4:
Step 5:
VHF
la
BAND
Step 1: Connect a DC SSVM to TP5 and ground.
Step 2: Program CH1, 2 and 3 as follows:
CH1 (30 MHz), CH2 (40 MHz), CH3 (54 MHz).
Select Channel 3 (54 MHz) and adjust TC3
for
13V
on the DC SSVM.
Select Channel 1 (30 MHz) and adjust T7
for
1.0V on the DC SSVM.
Repeat steps 3 and 4
until
no improvement is observed. The DC SSVM should read
as
below.
30 MHz Voltage at TP5 0.9 - 1.0V
40 MHz Voltage at TP5 4.1 -
4.5V
54 MHz Voltage at TP5
12.5-13.1V
REFERENCE FREQUENCY osc
AlIGNMENT
Step 1: Connect Frequency Counter
to
07
Collector through a ceramic eapacity (47 - 100 pF) and
ground.
Step 2: Select Channel 2 (40 MHz) and observe vca Frequency.
Step 3: Adjust TC6 so
that
the frequency is 50.700 MHz ±20 Hz.
Step 4: Repeat
VHF
la
BAND
vca
AlIGNMENT.
AI
RCRAFT
Hl
BAND
AND
UHF
BAND
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Connect a DC SSVM to TP-5 and ground.
Program CH1, 2, and 3
- 9 asfollows:
CH1 (108 MHz), CH2 (380 MHz), CH3 (138 MHz), CH4 (120 MHz), CH5 (150 MHz), CH6 (450
MHz), CH7 (136 MHz), CH8 (174 MHz), CH9 (512 MHz).
Select Channel9 (512 MHz) and adjust TC4
for
13V on the DC SSVM.
Select Channel 1 (108 MHz) and adjust T8
for
1.0V on the DC SSVM.
Repeat steps 3 and 4
until
no improvement is observed. The DC SSVM should read as below.
108 MHz Voltage at TP5 0.9 - 1.1V
380 MHz Voltage at TP5 1.2 - 2.0V
138 MHz Voltage at TP5 1.8 - 2.5V
120 MHz Voltage at TP5 2.2 -
3.0V
150 MHz Voltage at TP5 3.7 - 4.7V
450 MHz Voltage at TP5 5.5 -
6.6V
136 MHz Voltage at TP5 5.6 - 6.5V
174 MHz Voltage at TP5 9.8 - 11.0V
512MHz
Voltage at TP5
12.5-13.1V
-9-
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General