Technical Manual
© SPECTRA ENGINEERING 2006 Revision 4.2.2
90
6. MX800 Base Station Fault
Finding Procedure
The following test equipment may be required for the following tests:
MXTOOLS (MX800 Base Station Programming Utility)
RF Test Set (eg HP 8920 or equivalent)
CRO (Cathode Ray Oscilloscope)
RF Power Meter (capable of measuring to 60 Watts continuously)
Multimeter
+13.8V DC Power Supply (capable of supplying 15Amps)
Network Analyser
MX800 test jig (Optional)
6.1 MX800 Base Station
(The following tests will help diagnose faulty modules)
Check that all of the required connections to the MX800 Radio are made.
Check that all of the interconnecting cables to each of the modules and to the
Motherboard are correctly installed.
Check voltage supply to the MX800 by measuring both sides of Fuse 1
located on the Microcontroller PCB. Replace fuse if necessary.
Check that the power LED is lit. If not then go to section 6.2.
Using MXTOOLS check that the frequency tables and configuration settings
are correct.
6.1.1 Transmitter Section
Connect the output of the Power Amplifier Module to a Comms test set or a
RF power meter.
Using MXTOOLS Diagnostic’s check the TXVCO locking voltage is
between 2 – 18 V and there is no TXVCO ‘Unlock’ alarm displayed.
If the locking voltage is out of spec or an ‘Unlock’ alarm is displayed then go
to section 6.4
Key up the transmitter using the software PTT in MXTOOLS or by shorting
pins 10 (Earth) & 12 (PTT) of CN1 the 15-way connector at the rear of the
radio to ground.
If the output power of the MX800 is LOW then using MXTOOLS check that
the ‘Transmit Power’ control is not on a low setting.
Adjust the ‘Transmit Power’ control towards maximum looking for an
increase in the RF power output level. If there is no substantial change go to
the diagnostics screen and check that the Forward power and the Reflected
To Next Page
Loading...