User's Manual

Table Of Contents
6881094C31-C October 14, 2003
Troubleshooting Charts: RX RF 5-23
5.14 RX RF—Page 1
Frequency OK?
VHF: 44.85 MHz
UHF: 73.35 MHz
700-800: 109.65 MHz
Inject a standard FM test signal
into the antenna port. Use CPS to
ensure that attenuator feature is
disabled. Use a spectrum analyzer
and high-impedance RF probe to
measure the IF signal at TP12
(700-800) or TP15 (VHF) on side 2
No
No
Ye s
Ye s
Poor RX
sensitivity or
no RX audio
Check
RXLO
Replace
bad part
Remove cable
assembly, measure
insertion loss
Visual
inspection
OK?
No
Ye s
Bad antenna connector.
Replace chassis
(connector is not
serviceable)
Loss
< 0.2 db?
Replace
cable assembly
No
Ye s
Inspect coaxial
antenna connector
and cable assembly
Measure RF
input level
at TP02
Measure RF levels at TP02
and TP13 (UHF & 700-800)
or TP401 (VHF),
compute SW_FL loss
RF level
about
-47 dBm?
No
Ye s
SW_FL
loss < 2 dB?
Check
SW_FL
Ye s
No
IF
level about
-38 dBm?
1
2
3 kHz FM deviation,
1 kHz rate, -47 dBm
MAEPF-27470-B