TM 11-6625-847-45
4-5. Test Set A2, Dc-to-Dc Converter Module A2; Voltage, Regulation, and Ripple Tests
Dc-to-dc converter module A2 (fig. 4-1) (module A2) is on the boom plate in the beck of the front panel of the test
set (fig. 3-10) and is secured by four hexagonal nuts. Module A2 (fig. 4-1) is an encapsulated unit and is not repairable.
If any of the performance standards are not satisfied, replace module A2.
a. Test Equipment and Materials,
(1) Multimeter AN/PSM-6B.
(2) Oscilloscope AN/USM-140.
(3) Resistor: 1,000 ohms, 50 watts.
(4) Charger, Battery PP-1451/G.
(5) Resistor: 260 ohms, 15 watts.
c. Procedure.
Step
Control settings
No.
Test equipment
Equipment under test
Test procedure
1
AN/PSM-6B
POWER switch: OFF
a. Set the DC VOLTAGE 200
The voltage should vary from
less tha
FUNCTION switch:
SERV SEL switch: OFF
control to approximately
DCV-20KΩ/V.
PA/RT switch: PA
midrange.
more th
RANGE switch: 250.
KEY switch: OFF
b. Connect the AN/PSM-6B dc
the volt
XMIT STATUS switch: OPR
test leads to the PP-1451/
REC-XMIT switch: REC
G output terminals to
ALC VOLTAGE INFO control:
check the output voltage.
Fully counterclockwise
c. Set the PP-1451/G NORMAL
ALC VOLTAGE TUNE con-
CHARGE switch to NOR-
trol: Fully counterclockwise
MAL and the power switch
IF OSCILLATOR select switch:
ON. Set the VOLTAGE
4.
ADJUST control for an
MC FREQ 10MC switch: 0
output of +27 volts dc on
MC FREQ 1MC switch: 0
the AN/PSM-6B.
MC FREQ 1MC switch: 0
d. Turn the PP-1451/G power
500 VDC LOAD switch: LOW
switch to OFF, and discon-
2400 VDC LOAD switch: 1
nect the AN/PSM-6B.
e. Connect the AN/PSM-6B
across terminals 3 and 4
of module A2 between
+200 DC VOLTAGE test
point A1J3, on the front
panel of the test set and
DC VOLTAGE (ground)
test connector A1J2.
f Turn the test set SERV SEL
switch to OVEN ON and
the power switch to ON;
set the PP-1451/G power
switch to ON.
g. Turn the DC VOLTAGE
200 control from fully
counterclockwise to fully
clockwise.
h. Turn the PP-1461/G power
switch to OFF, and the
test set power switch to
OFF.
2
Same as step 1 above.
Same as step 1 above.
a. Connect the AN/PSM-6B
1% of the value in step 1 above.
dc test leads to the PP-
1451/G output terminals.
Energize the PP-1451/G.
Adjust the output voltage
to +26 volts or to +24
volts if the PP-1451/G
can be adjusted to that low
value. Turn the PP-1451/G
off, and remove the AN/
PSM-6B leads.
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