TM 11-5985-355-13
Table 6-1. Troubleshooting Chart
Item No.
Trouble symptom
Probable trouble
Corrective measure
1
MX-9146/GRC will not tune or will not
Open wire in CX-13055/GRC.
select proper subband.
defective, repair cable.
2
MX-9146/GRC will not tune or r/t
Ware shorted to ground in
Check continuity of cable. If defective
unit t)lows fuse.
CX-13055/GRC.
repair cable.
+24-volt supply fuse when match-
3
Pin K on J2 short-circuited
to ground.
ground.
set on any band segment.
4
24-volt supply blows when new fre-
Pin D, E, F, G, or H on J2Same as 3 above.
Same as 3 above.
quency is selected
short-circuited to ground.
5
MX-9146/GRC will not tune to any band
No control voltage.
Check switch S1-A and connectorJ2 for
segment.
control voltages shown in figure FO-1.
Manually rotate knob of switch S1 to
check
S1 for binding.
6
Select subband in ascending order;
No control voltage on pin A
MX-9146/GRC tunes only to BAND
or B of J2 from radio
pin A of J2 with TS-352B/U for +24 volts.
2 frequencies.
through CX-13055/GRC.
7
MX-9146/GRC tunes to wrong subband
Open connection on J2 or
or cycles continuously.
short-circuited J2 connector.
ground (fig. FO-1).
8
MX-9146/GRC will not pass rf (all
Open coaxial connector or rf
a. Check for continuity from input
bands).
cable assembly
connector J1.to output connector J3 in 42-
47.5 MHz position (fig. FO-1).
cable assembly to connector J3. If
cable is open replace rf cable assembly.
c. Repair or replace MX-9146/GRC.
Figure 6-1. Antenna Element AS-2732/GRC, partial view, parts location.
(1) Removal.
6-7. Matching Unit-Base MX-9146/GRC Parts
(a) Remove six cap screws (SM-D-889206)
Removal and Replacement
and washers (MS35338-139B) and separate cable
a. Rf Cable Assembly (SM-D-889241) (fig. 6-2
mount assembly from the MX-9146/GRC.
and 6-3).
Change 2 6-2