TM 11-5895-846-14
If good signals are not received, replace the faulty LNA.
the ON LINE switch position, the LNA waveguide switch
n. Close the cover and secure the snap fasteners.
is not switching. Manual switching may be accomplished
by removing the power connector from the waveguide
5-55.
LNA Waveguide and Coaxial Transfer
switch, removing the top cover from the manual knob
Switches.
and turning the switch by hand. The RF cable connector
to the SHF OUTPUT of the LNA BITE must be
there is reason to believe that the LNA is functioning
connected directly to the SHF output of the desired LNA.
properly, the problem may be in one or both of the X-
5-56.
Removal and Replacement of LNA BITE
Band transfer switches.
a. Remove all cables from the LNA BITE.
a. If the correct ON LINE indicator is illuminated
b. Loosen the four captive screws which secure
on the LNA control/translator, the problem could be in
the LNA BITE to the mounting plate.
the coaxial transfer switch located in the LNA BITE. At
c. Remove the LNA BITE.
the LNA BITE, disconnect the RF cable from the SHF
CAUTION
OUTPUT jack and connect this cable directly to the SHF
output of the on-line LNA. If this solves the problem,
Remove the LNA BITE with care and do
not drop it.
d. Replace the LNA BITE by performing steps a,
system may be operated in this configuration until a
b, and c above in reverse order.
replacement LNA BITE can be installed.
b. If the ON LINE indicators at the LNA
control/translator remain in the same state regardless of
Section XVI. MAINTENANCE OF WAVEGUIDE SWITCH
e. Remove the four screws that secure the right
5-57.
Scope
port and the switch to the waveguide support bracket
Maintenance of the shelter transmit waveguide switch
(behind the switch).
(HY2) is limited to removal and replacement of the unit.
CAUTION
5-58.
Removal and Replacement of Waveguide
Exercise care not to scratch the
Switch
waveguide or the switch port mating
The switch is located inside the shelter (roadside) in
surfaces when performing step f below.
the top of rack 3 over the power amplifier unit.
a. On the RF and waveguide switch feed-through
between mating surfaces is not
panel; loosen the waveguide captive fastener and ten
damaged.
Phillips head screws.
f.
Remove the switch slowly while providing
b. Disconnect the waveguide interlock connector,
clearance for the gasket and mating surfaces.
remove the PA selector knob and four captive panel
NOTE
screws, and remove the panel from the rack.
When replaceing the switch, be sure not
c. Inside of panel opening, remove the connector
to dislodge the gasket on the waveguide
from the waveguide switch and four hex screws and
ends.
washers from each of the three ports (left, bottom, and
g. To replace the switch, perform steps a through
top).
f above in reverse order.
d. Remove the four screws securing the rear of
the switch to the ceiling bracket.
the opening stops on the drawer slide assembly).
5-59.
Scope
(3) Remove input and output cables from rear
This section contains instructions for removal and
of unit.
replacement of communications subsystem units.
(4) Disconnect all associated cabling from ac
5-60.
outlets located at rear of rack.
a. Removal and Replacement of C/N Test Set,
(5) Depress slide stop tabs and slide unit
A1(TS-3580).
outward until clear of slide tracks.
(1) Turn the power switch to OFF.
(6) Reinstall unit following steps (1) through
(2) Loosen all captive screws securing front
(5) above in reverse order.
panel to rack and pull on edges of front panel to extend
the drawer to its maximum open position (as allowed by
5-76