2. Refer to Table 3-3 and set Switching Units SA
115 VAC IS PRESENT AT TB 3 AND
2139 for DS-9 mode.
Selection of DS-9 mode permits
system operation to continue using
13. Loosen the three screws which secure synchro
MTR-2 (S-band) and Indicators A and
B while the following procedure is
minimum voltage reading (null) on the multimeter.
Tighten the three screws which secure synchro B3.
3. At Antenna Pedestal AB-1247A (X-band):
14. Set Signal Data Converter CV-3442 POWER
switch to OFF.
a. Set Safety switch to OFF.
15. At Antenna Pedestal
b. Disconnect and tag external leads at TB3
terminals 3, 4 and 5.
a. Remove jumper between TB3-2 and TB3-
During the following steps, the
b. Connect external leads at TB3 terminals
3, 4 and 5.
clockwise (as viewed from above),
16. Set the second multimeter to the 250 Vac scale
even if it means making a full
and connect it between TB3-3 USA) and TB3-S (53);
rotation. Moving the antenna back
reduce the voltage settling progressively to 2.5 VAC as
and forth causes the normal
alignment is achieved in step 17 following .
backlash in the gears to bearing
17. Set Signal Data Converter CV-3442 POWER
introduce errors .
switch to ON.
4. Remove the cover plate from the front of the
antenna pedestal and loosen the locking nut on the
First verify multimeter indicates a
syncro adjustment arm. Position the arm at the middle
short circuit before proceeding .
of the guide wire and snug the locking nut.
18. Loosen the locking nut on the synchro
5. Manually rotate the X-band antenna clockwise
adjustment arm and carefully adjust the arm position to
until the face is pointing slightly to the left of the bow
obtain zero Vac reading on the multimeter; tighten the
(approximately 340 relative); maintain this position
locking nut, insuring that the zero Vac reading is
through step 6 following.
6. Disconnect the waveguide from the rotary joint
19. Set Signal Data Converter CV-3442 POWER
and loosen the captive screws which secure the
switch to OFF.
pedestal housing to the base plate. Tilt the housing up
20. At Antenna Pedestal:
into its service position.
a. Disconnect multimeter and reconnect
7. Remove external leads a t TB1 terminals 10, 13
external leads at TBI terminal 10,13.
and TB3 terminals 3, 4, and 5. Connect a multimeter,
b. Carefully lower the pedestal housing and
tighten the captive screws in the base
c. Connect the waveguide to the rotary joint.
measurement, between TB1-10 and TB1-13.
d. Set Safety switch to ON.
9. Slowly rotate the antenna clockwise, stopping
21. Set Indicator C (master for MTR-I, X-band)
when the multimeter indicates a short circuit (heading
POWER switch to TX ON.
flash switch closure).
22. Set POWER switches to ON at the following
Maintain the multimeter connections
a. Video Amplifier AM-6932
at TB1-10 and TB1-13; check the
b. Signal Data Converter CV-3442
multimeter reading prior to each of
the following steps to insure that
c. AN/SPA-25 and AN/SPA-66 indicators
switch closure is maintained.
23. At Signal Data Converter CV-3422, select
10. Install a jumper between TB3-2 (R2) and TB3-S
relative bearing (RB) display for AN/SPA-25 and
11. Connect a second multimeter, set to 250 Vac
24. At AN/SPA-25 indicator, select display from
scale, between TB3-1 (R1) and TB3-4 (52).
AN/SPS-64(V) radar; verify heading line is displayed at
0relative (see notes following next step) .
12. Set Signal Data Converter CV-3442 POWER
switch to ON.
25. Repeat step 23 for AN/SPA-66 indicators.