(8) Tighten Allen-head screws in retract and extend
limit microswitch cams securely.
Elevation Antenna AS-1291/TPN-8 may be
(9) Servo elevation Antenna AS-1291/TPN-8
positioned by hand by rotating knurled end of
accurately to 15 degrees left as indicated on elevation
drivemotor shaft located under cover on right
(10) Loosen two setscrews in data potentiometer
side of elevation Antenna Drive TG-114/TPN-8.
coupler farthest from data potentiometer. (Do not loosen
two setscrews nearest to data potentiometer.)
(3) Position elevation Antenna AS-1291/TPN-8 to
(11) On vtvm, place SELECTOR switch to (-) and
scan angle of 0 degree as indicated on clinometer.
RANGE switch to 10V.
Maintain scan angle of 0 degree while performing steps
(12) Connect COMMON lead of vtvm to braided
(4) and (5) below.
ground lead in elevation Antenna AS-1291/TPN-8
(4) Observe that rollers of 10-degree unblanking
actuator. Connect DC lead to center terminal of data
cam microswitch S501 (right), 35-degree unblanking cam
microswitch S502 (middle), and simultaneous-elevation
(13) Carefully rotate data potentiometer coupler to
gate cam microswitch S503 (left) are on lobes (high part)
obtain -1.0 volt indication on vtvm.
of respective cams. If not, loosen locking screw and
(14) Tighten two setscrews in coupler securely,
position respective cam so that microswitch roller is on
being careful not to rotate coupler.
(15) Check vtvm indication to ensure indication is
(5) Loosen locknut on depth (adjusting) screw of
still -1.0 volt. Disconnect vtvm.
each microswitch. Adjust depth screw of each
(16) Position cover and gasket in rlace and secure
microswitch 1/4 turn past point at which microswitch
with 10 screws. Insure gasket provides good
actuates. Tighten locknut.
(6) Insure that clamp screw on gear at center of
camshaft is tight.
3-20. Antenna Drive TG-114/TPN-8 Cam Alignment
(7) Position elevation Antenna AS-1291/TPN-8 by
hand to scan angle of -1 degree as indicated on
clinometer. Maintain scan angle of -1 degree while
a. Test Equipment Required. Clinometer MP3502
performing steps (8) and (9) below.
(8) Loosen locking screw in 10-degree unblanking
cam (right) and position cam so that front edge of cam
lobe just actuates microswitch S501. Tighten cam locking
b. Equipment Conditions.
(1) Radar set group must be level.
(9) Loosen locking screw in 35-degree unblanking
(2) If Radar Set AN/TPN-18 is turned on, place
cam (middle) and position cam so that front edge of cam
lobe just actuates microswitch S502. Tighten cam locking
RT-818/TPN-18 control panel to OFF, for safety of
(10) Position elevation Antenna AS-1291/TPN-8 to
scan angle of -4.5 degrees as indicated on clinometer.
Maintain scan angle of -4.5 degrees while performing
step (11) below.
References to part locations and directions for
(11) Loosen locking screw in simultaneous
positioning (left, middle, right, etc.) are as viewed
elevation gate cam and position cam so that front edge of
cam lobe just actuates microswitch S503. Tighten cam
(1) Remove screws and top cover at front of
elevation Antenna Drive TG-114/TPN-8 housing for
Do not replace top cover on elevation Antenna
access to cam and microswitch adjustments.
Drive TG-114/TPN-8 until the elevation angle
(2) Attach clinometer to clinometer mount on
data potentiometer has been aligned.
elevation Antenna AS-1291/TPN-8.