Motorola ASTRO XTS 5000 - TX RF (VHF and UHF Range 2)

November 16, 2006 6881094C31-E
5-36 Troubleshooting Charts: TX RF (VHF and UHF Range 2)
5.15 TX RF (VHF and UHF Range 2)—Page 1
TX
power OK?
Place XCVR and VOCON
into the analysis fixture.
Key up. Measure RF
power at antenna port
Ye s
No
Ye s
No
No or low
TX power
Check
FGU
Frequency
OK?
No
Ye s
Check
FGU
Level
about
-3 dBm?
Check coaxial
connector and
cable assembly
Measure RF level
at Q107 pin 2
Use a spectrum analyzer
and high-impedance RF
probe. Measure TXRF
at C016
Level about
+15 dBm?
No
No
Ye s
Ye s
Level about
0 dBm?
No
Measure
drain of
Q104
Measure RF
level
at C147
Ye s
Remove SH701
and check for
parts off pad
Check bias of Q101,
Q103, and Q106.
Replace bad
transistors
Is voltage
5 V?
1
2
MAEPF-27635-O