Kenwood FM Transceiver TK-481 Service Manual page 40

Item Condition
22. BATT 1) SYS – GRP : 4 – 1
detection BATT terminal voltage : 5.7V
check PTT : ON
2) BATT terminal voltage : 6.5V
PTT : ON
Note : When the CPU is changed these adjustment values will become suitable values for NPSPAC, the deviations except MAX DEV in NPSPAC band
are automatically adjusted.
Receiver Section
Item Condition
1. Sensitivity 1) SYS – GRP : 1 – 1
check SSG output : –116dBm
MOD : 1kHz
DEV : 3kHz (TK-480)
: 1.5kHz (TK-481)
2. Squelch 1) SYS – GRP : 4 –
adjustment Select SQL
in tuning mode.
SSG output : 3dB below to
12dB SINAD level
3. Squelch 1) SYS – GRP : 4 – 1
check SSG output : 12dB SINAD level
See Note. 2) SSG output : OFF
Note : When squelch is adjusted, the microcomputer simultaneously reads and writes the RSSI level. Do not write adjustment values without the SSG
connected.
ADJUSTMENT
Measurement
Test-
Unit Terminal Unit
equipment
Power meter Panel ANT Panel
Deviation
meter
Oscilloscope
AG
AF VTVM
Measurement
Test-
Unit Terminal Unit
equipment
SSG Panel ANT
AF VTVM
Oscilloscope
Distortion
meter
Panel
TK-480/481
Adjustment
Parts Method
Encoder Check Can not transmit.
knob LED (TX) blinks.
Transmit
Adjustment
Parts Method
Check 12dB SINAD or more.
Encoder Adjust to point of
knob closing squelch.
Check Squelch must be opened.
Squelch must be closed.
Specifications/Remarks
Specifications/Remarks
39