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TM-642A
ADJUSTMENT
Transmitter Section Adjustment
Measurement point
Adjustment point
Item
Condition
Test
Specification
equipment
Unit Terminal
Unit
Parts
M
ethod
1.
Power
1. Maximum power
check
Powermeter
Rear
ANT
TX-RX
VR3
Check
48 Wormore
adjustment
Frequency: 136.000 MHz
Ammeter
Panel
(check)
145.980
MHz
147.980 MHz
Transmit
2. High-power
adjustment
TX-RX
VR3
Adjust:
48W
47.5
to
48.5 W (11.5 A or
Transmit
less)
3. Medium-power adjust-
TX-RX VR4
AdJUSt 12W
1Qto
14W
ment
Transmit
4. Low-power
check
Check
3to8W
Transmit
2. Deviation
1.
Freql)ency:
145.980
MHz DC detector
Rear
ANT
TX-RX
VR2 Adjust
(in
the
±
4.0 to 5.0
KHz
adjustment
AG
:
1 kHz, 50 mV
Oscilloscope
Panel
higher+ or
-
(check)
direction).
4.2 KHz
Filter:
rnJ
K
Transmit
2. Frequency: 145.980 MHz
Check
±
2.
2
to
3 6 kHz
AG: 1
KHz, 5.0
mV
Transmit
3. Tone check
1.
Frequency:
144.980
M
Hz
DC
detector
Rear
ANT
Check
±
0.5 to 1.5
KHz
Tone
On
Oscilloscope
Panel
Transmit
4.
Protection
1.
Frequency:
147.980
MHz
Ammeter
Check
12.0 A or less
check
Antenna: open
Transmit
5.
Frequency
1
.
Frequency:
145.980
MHz
Frequency
TX-RX
TC1
145980
MHz
±100Hz
adjustm
ent
Transmit
counter
Powermeter
I
0
o
L
00
0
0
0
:?
~
0
0
0
0
®V
R3
L1
©
VR4®
VR2
TC1
D
®
VR1
L2©
®
®
0
-?P2
L6
[Q)
L4©~
........
0
0
0
"\_
Note:
Use an adjustment tool
with
a ceramic or
plastic tip
1.5
mm sq
ua re
for L 1
t hrough L4.
Fig
.
57 144 MHz band adjustment: Component layout (upper view)
28
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