6871620L01-C
May 28, 2008
Troubleshooting Charts:
RX RF
5-25
RX RF–Page 5
Measure preselector filter
tuning voltage dac2 at
VHF:
C413
UHF:
C420
Replace IF filter.
VHF/ UHF:
FL490
Repair
defects
6
8
Visual
inspection
OK?
Check IF filter and
LC matching networks.
No
Yes
Check discrete
preselector filters.
Replace
PCIC
Dac
voltages
OK?
Tune the radio across several
channels. Measure dac2,
proportional to frequency.
No
Yes
7
VHF
136
174
0.9
2.1
Band F (MHz) dac2 (Vdc)
UHF
380
470
0.9
3.1
Summary of Contents for ASTRO XTSTM 4000
Page 1: ...COLOR CHORDS 7 ASTRO XTSTM 4000 Portable Radio Detailed Service Manual ...
Page 2: ......
Page 16: ...May 28 2008 6871620L01 C xiv Commercial Warranty Notes ...
Page 22: ...May 28 2008 6871620L01 C 1 6 Introduction Notes ...
Page 26: ...May 28 2008 6871620L01 C 2 4 Radio Power Notes ...
Page 56: ...May 28 2008 6871620L01 C 3 30 Theory of Operation Notes ...
Page 100: ...May 28 2008 6871620L01 C 6 8 Troubleshooting Waveforms Notes ...
Page 194: ...May 28 2008 6871620L01 C B 2 Motorola Service Centers Notes ...
Page 204: ...May 28 2008 6871620L01 C Glossary 10 Glossary Notes ...
Page 209: ......