Ericsson ORION - Additional Tool Required; Transmitter

LBI-3890
8
17
ADDITIONAL TOOLS REQUIRED:
• RF Power Attenuator (30 dB, 150 watt, for transmitters with RF power beyond capability of the Service Monitor)
• Digital Voltmeter
• Oscilloscope (Optional)
TRANSMITTER
SYMPTOM DIAGNOSTIC PROCEDURE
No RF power output a) Program a conventional system with frequencies given in Table 2 or 3. Use the
"EDACS3" PC Programming utility.
b) Check RF Power Tracking Data, using the "MRKMAINT" PC programming
utility. Data should be the same as that shipped with the radio. If fail, re-enter
Tracking data using procedure given in the "Tracking Data" Section of this
manual.
c) Check TP1 on PA board for A+. If not there, check power cable fuse.
d) Key the radio and measure the DC voltage at TP4 (9 Vdc typical, when keyed). If
not there, trace TXENABLE signal back to Logic board.
e) Unscrew PA module from rest of the radio unit. Remove P1 from J151 and connect
an RF wattmeter to J151. Power should be 400-700 mW. If not, replace
Synthesizer board and reload the Modulation Tracking Data. If the correct power
level is there, replace PA board.
Frequency too low/high Adjust the reference oscillator XU201 on the Synthesizer board. If the frequency still
not correct, replace the Synthesizer board.
Low or no modulation a) Program a conventional system with frequencies given in Tables 2 or 3. Us the
"EDACS3" PC programming utility.
b) Check the Modulation Tracking Data, using the "MRKMAINT" PC
programming utility. The data should be the same as that shipped with the radio. If
not, re-enter the Tracking Data using the procedure given in the "Tracking Data"
section of this manual.
c) Apply a 1000 mVRMS, 1 kHz audio signal to the microphone connector, Pin 1
(Pin 2 is ground reference). Key the radio (make sure the antenna connector is
connected to the proper 50 ohm load). Check for an audio signal at TP202 on the
Synthesizer board. If not there, replace the Synthesizer board and reload the
Modulation Tracking Data.