(1) Remove the six pan-head screws and flat
elevation) to gain better access to the
washers (1, 2). Carefully separate the connector plate
selected petal. This task should not be
(3) from the actuator (4) to expose the terminal board.
attempted if winds exceed 40 mph (64
(2) Disconnect the numbered wires from
terminals 1 through 7 on the terminal board.
(3) Remove the four socket head screws and
(1) If necessary, place the antenna in the
flat washer (8, 9) and slide out the motor-brake-
d. Motor-Brake Tachometer Replacement (fig. 5-
If the petal being removed is the upper
one, it will be necessary to loosen the
(1) Carefully guide the motor and brake wires
toward the terminal board located under the connector
and remove the probe and its cable.
plate (3) while sliding the motor-brake tachometer (10)
into the actuator (4).
(2) Using the 5/8-inch hex tool, release the
(2) Use the locking-compound (MIL-S-22473)
latches on the petal to be removed and on the adjacent
and install the four socket head screws and flat washer
panel. Rotate the tool 3/4 turn clockwise to release the
(8, 9) to secure the motor-brake-tachometer (10) to the
(3) Hold the petal firmly and unlock; release
(3) Connect the numbered wires for the
and remove the two quick-release pins which hold the
motor-brake tachometer to terminals 1 through 7 on the
petal to the center section.
(4) Carefully remove the petal.
(4) Use the locking compound (MIL-S-22473)
(5) Replace the petal by performing step (1)
and install the six pan head screws and flat washers (1,
through (4) above in reverse order.
2) to secure the connector plate (3) to the actuator.
Removal of Antenna Feed Tube Assembly.
e. Removal of Antenna Petal (fig. 5-26). Any one
(1) While holding the feed tube, unscrew and
of the four antenna petals (quarter sections) may be
remove the feed tube.
removed and replaced on the antenna without removal of
(2) Detach the feed cover from its stowed
the other three petals.
position on the feed flange.
(3) Place the feed cover over the feed flange
The task will require two persons if it is
and screw it in place.
desired to raise or lower the antenna (in
Section XIV. MAINTENANCE OF PARAMETRIC AMPLIFIER AM-6700/TSC
This section contains instructions for the testing, removal
before testing; erroneous indications will occur if tests
and replacement of the low noise amplifier (LNA). There
are performed during the warm-up period.
are no modules in the LNA which can be removed at the
organizational level. If an LNA is found to be faulty, it
The FAULT indicator on the LNA
should be removed and replaced and returned to the
CONTROL panel (LNA control) will be
next higher level of maintenance.
illuminated during the warmup period (5
to 8 minutes).
After warmup (and
Testing and Fault Isolation
assuming the indicator turns off), the
FAULT indicator then serves to signal a
The following procedures are based on use of built-in-
fault in the LNA. An unusual power-
test-equipment at the LNA control/translator, the
failure type of fault could occur that
downconverter, and the LNA BITE; no additional test
equipment is required. It must be assumed here that
the LNA control FAULT and POWER
these units are known to be in good operating order (an
indicators (unit faults probably will be
LNA-related fault may cause the downconverter to
indicate a unit fault). Test procedures are described for
modem, and MUX). If so, transpose the
both the on-line and standby LNA. The GO, NO- GO
position of the two LNA controls (para 5-
testing of a suspected faulty LNA is performed with the
41). If the fault moves with the module,
LNA in the standby position using the LNA BITE test
that module is defective. If the fault
oscillator. The suspect LNA must be fully warmed up
moves in the unit module position, the
control/translator drawer is probably
defective; refer the unit to higher level