Removal and Replacement of Feedhorn

TM 11-5985-335-15

(2)

Remove the cap screw (fig. 2-6), lockwashers and washer securing the tilting assembly to the

backmount, and remove the tilting assembly.

Replacement

(1)

Attach the tilting assembly to the backmount using the cap screw, lockwasher, and washer removed in

step a. (2) above.

(2)

Align the screw insert in the rod cap of the tilting assembly with the reflector flange bracket hole, and

secure with the tee bolt (fig. 2-4).

(3) Pull on the tilting rope to insure that the tilting assembly operates.

4-5.

Removal and Replacement of Feedhorn.

(fig. 2-7)

Removal

(1)

Unscrew the power connector plug (not shown) from the deicer receptacle.

(2)

Screw the connector cover on the deicer receptacle.

(3)

Release the quick-disconnect clamp and move Waveguide Assembly CG-3251/GRC aside.

(4)

Unscrew four wing bolts.

(5)

Carefully remove the feedhorn from the reflector.

Replacement

(1)

Check the arrows on the reflector for the polarization desired (fig. 2-6).

(2)

Orientate the feedhorn and place it in the reflector opening from the rear.

(3)

Screw in the four wing bolts (fig. 2-7).

(4)

Place Waveguide Assembly CG-3251/GRC against the feedhorn and close the quick-disconnect clamp.

Note: Perform (5) and (6) below if use of deicer is anticipated.

(5)

Remove the connector cover from the deicer receptacle.

(6)

Screw the power connector plug (not shown) on the deicer receptacle.

4-6.

Removal and Replacement of Feedhorn Iris.

Removal

(1)

Remove the 10 screws and self-locking nuts securing the outer frame of the feedhorn iris, and remove

the outer frame.

(2)

Remove the gasket and iris.

Replacement

(1)

Place the iris and gasket against the feedhorn.

(2)

Place the outer frame against the gasket and iris, and replace the 10 securing screws and self-locking

nuts removed in a. (1) above. (One of the self-locking nuts is used to secure the ground wire of the heater assembly, as

shown in figure 4-1).