TTI TCB-550, Service Manual

Page: 15 / 39

5-2. Transmitter Section Alignment
5-2-1. Required Test Equipment : If uses in HP8920, the 1)~7) equipment is not a necessity.
1) RF Power Meter
2) 50 ohm Load (non-inductive)
3) RF attenuator (30dB)
4) Audio Generator
5) Modulation meter 6) Frequency counter
7) DC Voltmeter
8) Spectrum analyzer
9) DC power supply: 13.8VDC / 3A
10) Oscilloscope
5-2-2. Alignment procedure
Step Test Item UUT setting Equipment setting
Alignment
point
Spec.
1
TX
Frequency Channel: CH19
Function:
1) AM or FM mode
2) CB
Unit: TX condition
Adjustment
(MIC PTT on)
Others: Don’t care
Connect the equipment and
UUT as shown on Figure.2
CTX1
27.185MHz
+/-300Hz
2
TX
Power Channel: CH19
Function:
1) AM or FM mode
Adjustment
DC power supply : 15.6V
Unit: TX condition
(MIC PTT on)
Others: Don’t care
Connect the equipment and
UUT as shown on Figure.3
Max.4W
LT1
LT2
( If cannot
get a power
up to 4W,
adjust VR3 )
3
AM Modulation Channel: CH19
Function:
1) AM mode
2) CB
Unit: TX condition Adjustment
(PTT on)
Others: Don’t care
Connect the equipment and
UUT as shown on Figure.3
Audio generator
1) Set to 1KHz / 50mV
2) Input to MIC
Adjustment:
1) Adjust RVM1 to obtain
85% modulation
RVM1 Max : 90 %