Service manual

TH-K4AT/K4E
40
ANT
ANT
MIC
LCD
VR6
VR5
Check
By tuning the
VR6, adjust
the modulation
wave until
if becomes the
square wave.
4.2kHz
According to the
larger +, –.
Change the AG
output level to
obtain 3kHz
deviation.
4 to 6 seg-
ments are
lighted.
■■■■ ~
■■■■■■
±0.1kHz
4mV - 12mV
Item Condition
Measurement Adjustment
Specifications/
Test equipment Unit Terminal Unit Parts Method
Remarks
4.DCS
modulation
balance
5.MAX DEV
6.MIC
sensitivity
Check
To exit from the Adjustment
Mode, turn the transceiver
power OFF and then ON.
2)Frequency: 435.000MHz
PTT: ON
Battery terminal voltage: 6.4V
Switch to Adjustment mode
and carry out the operations
for adjustment item L.
(Refer to page 33)
Detector: +P, –P
HPF: OFF LPF: 3kHz
De-emphasis: OFF
TX power: Low
1)LCD display: DCS.BAL
Frequency:435.000MHz
PTT: ON
To exit from the Adjustment
Mode, turn the transceiver
power OFF and then ON.
MIC terminal input
AG: 1kHz/80mV
Detector: +P, –P
HPF: OFF LPF: 15kHz
De-emphasis: OFF
TX power: Low
1)Frequency: 435.000MHz
PTT: ON
MIC terminal input
AG: 1kHz
Detector: P-P/2
HPF: OFF
LPF: 15kHz
De-emphasis: OFF
TX power: Low
1)Frequency: 435.000MHz
PTT: ON
DC power supply
DVM
Linear detector
Oscilloscope
Linear detector
AG
Oscilloscope
TX-RX
(A/3)
ADJUSTMENT
(Adjust the output voltage from DC power supply until the voltage at the
battery terminal becomes 6.4V while the transceiver is transmitting.)