TM 11-5822-225-35
3-21.1. Inverter Frequency Adjustment
(4) Set the BFO-OFF switch on the con-
trol unit to OFF.
NOTE
(5) Adjust the output of the signal gen-
erator to 40 microvolts.
Capacitor C6 is selected from 2.2 F, 3.3
(6) Set the function switch on the control
F, 3.9 F, 4.7 F, 6.8 F, or 10 F to ob-
trol unit to LOOP.
tain a frequency of 400 40 Hz from the
(7) Note the indication of the BEARING
inverter. This selection is necessary due
INDICATOR on the test set.
to variations in components of the in-
(8 Adjust the LOOP control on the con-
verter circuitry.
trol unit so that the indication on the
BEARING INDICATOR is 175 de-
a. Remove two screw's that secure the protec-
grees to the right or left of the indi-
tive plate marked INVERTER on the front panel
cation in (7) above.
of the test set.
(9 Observe the BEARING INDICATOR,
b. Disconnect the inverter that is normally part
return the function switch on the con-
of the test set.
trol unit to ADF, and measure the
time required for the BEARING IN-
c. Connect cable W4 of the test set between P1
DICATOR to reposition at the indi-
on the inverter and the connector marked
cation in (7) above.
INVERTER on the test set.
(10) The time required in (9) above should
not exceed 7 seconds.
d. Connect cable W1 of the test set between J7
on the test set and a +27.5-volt dc power source.
n. If necessary, readjust R131 to meet the
requirements of l and m above. Then tighten
e. Set the test set RECEIVER-CONTROL
the locknut on R131.
switch to CONTROL.
f. Connect the frequency meter to the test point
3-21. Inverter Voltage
Adjustment
located in the center of the 1A fuseholder cap on
a. Remove two screws which secure the pro-
the test set.
tective plate marked INVERTER on the front
panel of the test set.
g. Refer to figure 2-2.5. Loosen the locknut on R1
and position R1 fully clockwise.
b. Disconnect the inverter which is normally
part of the test set.
h. Refer to figure 2-25 and note connections for
c. Connect cable W4 of the test set between
capacitor C6. Unsolder and disconnect both leads
P1 on the inverter and the connector marked
of C6.
INVERTER on the test set.
i. Select a value for C6 (2.2 F, 3.3 F, 3.9 F,
d. Connect cable W1 of the test set between
4.7 F, 6.8 F, or 10 F) and connect to terminals
J7 on the test set and a 27.5-volt dc power
noted in step h.
source.
e. Set the DC POWER switch on the teat set
j. Set the test set DC POWER switch to ON and
to ON.
note frequency on frequency meter,
f. Set the RECEIVER-CONTROL switch on
the test set to CONTROL.
Ii, Repeat steps i and j to select a value for C6
that will provide a frequency of 400 40 Hz from
g . Connect the ac voltmeter to the test
the inverter.
point located in the center of the 1A fuse
holder cap on the test set.
1. After the proper capacitor value is deter-
mined, set the test set DC POWER switch to OFF.
h. Loosen the locknut on R1 (fig. 2-25) on
Replace C6 with the new value.
the inverter, and adjust R1 for an indication
of 26 2.0 volts on the ac voltmeter.
m. Remove the frequency meter and connect
i. Tighten the locknut on Rl.
the ac voltmeter to the same test point.
3-30 Change 5
Previous Page
