TK-880/H (UHF) mobile service manual - The Repeater Builder's ...

TK-880/H
Receiver Section
Item
Condition
ADJUSTMENT
Measurement
Testequipment
Unit Terminal
Adjustment
Unit Parts Method
Specifications/Remarks
1. Discriminator 1) Set test mode SSG Rear ANT TX-RX L6 AF output maximum. Maximum point +0mV, –20mV.
CH : CH1 - Sig1 - Narrow panel (A/2)
SSG output : –53dBm AF VTVM ACC
AF : 0.45V/4Ω Oscilloscope (EXT.SP)
2. Sensitivity 1) Set test mode SSG ANT Adjust for
Select “SENS” in tuning mode.
maximum SINAD.
“L SENS” AF VTVM ACC
SSG freq’ Distortion (EXT.SP)
K : 450.050MHz
meter
K2 : 485.050MHz
Oscilloscope
K3 : 400.050MHz
AG
SSG output : –118dBm/0.31µV
SSG MOD : 3kHz
AF output : 1V/4Ω
2) “C SENS” Adjust for
SSG freq’
maximum SINAD.
K : 470.050MHz
K2 : 498.550MHz
K3 : 418.050MHz
3) “H SENS” Adjust for
SSG freq’
maximum SINAD.
K : 489.950MHz
K2 : 511.950MHz
K3 : 429.950MHz
3. Squelch 1) Set test mode Squelch closed
Select “SQL” in tuning mode.
once.
SSG freq’
Then squelch must
K : 470.050MHz
be opened.
K2 : 498.550MHz
K3 : 418.050MHz
SSG output : Value when 2dB
is subtracted from the
sensitivity value of 12dB
SINAD.
SSG MOD : 3kHz (Wide)
1.5kHz (Narrow)
4. Squelch 1) Set test mode Check Squelch must be opened.
check CH : CH1 - Sig1 (Wide/Narrow)
SSG output : 12dB SINAD level
2) SSG output : OFF Squelch must be closed.
(Wide/Narrow)
5. QT check 1) Set test mode
CH : CH1 - Sig5
SSG MOD
INT : 1kHz
EXT : 151.4Hz
SSG system MOD DEV
: ±3.75kHz
SSG output : 10dB SINAD level
2) CH : CH1 - Sig4 Check Squelch must be closed.
CH1 - Sig6
CH1 - Sig7
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