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Maintenance:
Low Band Troubleshooting Charts
3-23
IF Signal at
L301?
No
RF Signal at
T501?
RF Signal
at collector
Q509?
No
RF Signal at
C504?
No
RF Signal at
C147?
No or
Check transmit harmonic filter, antenna switch
and J101
Check filter between C147
& C504
Inject RF into J101
No
Yes
Check RF amp (Q509)
Stage
Check filter between Q509&
T301
Yes
Check T501, T502, D501,
R507, R508,
R509,C516,L508
Yes
1st LO O/P
310OK?
Locked?
Yes
Check FGU
Yes
Trace IF signal
from L301 to
U301. Check for
bad XTAL filter
No
Yes
U301 drain OK?
IF signal
present?
Before replacing
U303, check U303
voltages; trace IF
signal path
Yes
Biasing on
U301 OK?
Troubleshoot
biasing, AGC
circuits and U301
No
No
Yes
A
B
weak RF
Troubleshooting Flow Chart for Receiver (Sheet 2 of 2)
Содержание PR860
Страница 1: ...PR860 Two Way Portable Radio Detailed Service Manual ...
Страница 2: ......
Страница 5: ...iv Notes ...
Страница 9: ...viii Table of Contents Notes ...
Страница 13: ...Notes xii List of Figures ...
Страница 17: ...1 4 Introduction Radio Model Information Notes ...
Страница 51: ...2 34 Theory of Operation Voltage Control Oscillators VCO Notes ...
Страница 81: ...4 4 Schematic Diagrams Overlays and Parts Lists Flex Layout Notes ...
Страница 193: ...4 116 Schematic Diagrams Overlays and Parts Lists Low Band Section Notes ...
Страница 196: ......