Kenwood NXR-901 Service Manual page 82

NXR-901
Common Section
Item Condition
1. Setting 1) Connect the DC power output to the rear panel DC terminal (13.8V).
2) Connect the front panel COM port (D-sub 9-pin connector) to the PC serial port with a cross-wired cable.
3) Activate the FPU to go to the test mode.
2. Temperature 1) Receive unit (Celsius or
Sensor Fahrenheit)
2) Transmit unit (Celsius or
Fahrenheit)
3. Driver 1) Low
Amplifi er 2) Center
Power 3) High
(Pre ADJ)
4. VCXO 1) REF Low
Lock Voltage SSG frequency: 10MHz
–10ppm (9.9999MHz)
SSG output: 0dBm
2) REF High
SSG frequency: 10MHz
+10ppm (10.0001MHz)
SSG output: 0dBm
3) MOD Low
SSG frequency: 10MHz
–10ppm (9.9999MHz)
SSG output: 0dBm
4) MOD High
SSG frequency: 10MHz
+10ppm (10.0001MHz)
SSG output: 0dBm
5. Transmit 1) Low
VCO Lock
Voltage
2) High
(Adjustment)
6. Receive 1) High
VCO Lock
Voltage
2) Low
(Adjustment)
7. Reference 1) Connecting SSG to REF IN
Signal and 50-load parallel.
SSG frequency: 10MHz
The switching SSG output: 0dBm (224mV)
circuit to switch
the OCXO and
2) SSG frequency: 10MHz
the internal
SSG output: –7dBm (99.9mV)
reference oscil-
lation
8. VCXO 1) Confi rm that there is no
OCXO and external reference
input.
82
ADJUSTMENT
Measurement
Test-
Unit Terminal Unit
equipment
Ther- Room RX
mometer temper-
ature
TX
SSG Rear REF IN
DVM TX REF_
CV
(CN401)
REF IN
MB_
CV1
(CN303)
SSG Rear REF IN
Spectrum REF
analyzer OUT
F. counter Rear REF
PC OUT
Adjustment
Parts Method
PC Measuring room
ADJ temperature, write
the value with PC.
PC Value: 1 Fixed value writing
ADJ
Check 0.65V or more
2.35V or less
1.5V or more
2.6V or less
PC Value: 76~80
ADJ
Confi rm that the
value is 180 or less.
PC Value: 136~138
ADJ
Confi rm that the
value is 40 or more.
Check REF OUT: +5dBm or more
The OCXO LED (orange)
lights.
REF OUT: +5dBm or more
The OCXO LED goes off.
PC 10MHz ±0.05ppm
ADJ (9.9999995~10.0000005MHz)
It takes a time from movement
of adjustment value to stability.
Specifi cations / Remarks