 |
|||
|
|
|||
|
|
|||
| ||||||||||
|
|  TM 11-5820-509-35
Item
Indication
Probable trouble
Procedure
Note.
Place XMTR PWR switch (S103) to OFF before proceeding with the remainder of these tests.
c.
XMTR PWR switch circuit
c.
Check continuity from CR103
defective.
cathode to S103B-7, from
S103B-7 to S103B-8, from
S103B-8 to FL2-26. from FL2-13
to BATTERY TEST switch S3A
(NC) and check value of R118
(normal 1K ohms). Check
continuity from FL2-26 to FL2-
13 and check each terminal for
shorts to ground. Repair circuit
or replace defective component.
8
No sidetone, or low sidetone level,
a.
Sidetone detector circuit in
a.
Check continuity from J103 to
on transmit.
power amplifier compartment
FL2-17, check resistance of R116
defective.
(normal 2.2K ohms), R108
(normal 100 ohms), and check
CR101, C124, C125, C126, and
C140 for shorts. Repair circuit or
replace defective component.
b.
Sidetone circuit in PA filter
b.
Check continuity from FL2-17
box FL2 defective.
to FL2-4 and check each ter-
minal for shorts to ground.
Replace L210, C212, C225, or
C236 if defective.
c.
Sidetone circuit in main chassis
c.
Check continuity from FL2-4 to
defective.
J2-17. Repair as necessary.
d.
Sidetone circuit in audio
d.
Repair AM-3506/PRC-47 (para
frequency amplifier A1 defective.
3-13a ) or replace defective
module.
Warning:
Place the POWER-LIGHTS switch to POWER OFF, disconnect the primary power source cable from the front of RT-671/PRC-
47, and discharge the plate circuit capacitors and high-voltage filter capacitors in the power supply before proceeding with
the following test. Personal injury or death can result from these dangerous voltages.
9
Excessive non-linearity in power
a.
Feedback circuit in power
a.
Check continuity from C144 to
amplifier stage.
amplifier compartment defective.
J7-A2; check capacitors C105
and C144 for shorts; repair
circuit or replace defective
component.
b.
Feedback circuit in signal data
b.
Repair CV-1377A/PRC-47
translator A3 defective.
c.
Power amplifier grid bias
module.
adjusted incorrectly.
c.
Perform adjustment routine of
paragraph 327.
malfunctions to components on the main chassis of the
receiver-transmitter.
following procedures in the order for isolation of
Item
Indication
Probable trouble
Procedure
Connect power to the receiver-transmi1ter, attach the antenna simulator and the dummy load as for transmitter tests (fig. 3-
3) and place the front panel controls as follows: CW-FSK/VOICE switch to VOICE: OPR-TUNE switch to OPR; KILOCYCLES
indicator to 2225; XMTR PWR switch to LO.
1
Equipment does not switch to
a. Hand set ptt switch defective.
a. Replace handset and tighten
transmit mode when ptt switch
audio input connector.
on handset is pressed.
b. Handset ptt circuit on main
chassis defective.
J2-11, to P2-F, to P3-F, to FL2-
12; also from FL2-25 to S102
(COM 1) and from S102 (NO 1)
to S102 (NO 2) and to FL2-16.
Check continuity from FL2-3 to
P2-H, to P3-H, to S3B (COM),
to S2 (COM) and from S2 (NO)
to P3-F. Repair defective circuit.
3-85
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals