Hughes DIRECWAY AN4-074-DF - Manual (Page 37)

Chapter 3 • Installing the radio and antenna assemblies
1035567-0001 Revision A
21
Installing a shim for
vertical transmit
polarization Follow the instructions in this section only if installation
specifications or a service order states that vertical transmit
polarization is required.
If vertical transmit polarization is not required, go to Installing
the radio assembly on the feed arm on page 25.
The radio assembly is shipped with a horizontal transmit
polarization shim installed. If vertical transmit polarization is
required, you must remove the horizontal shim and replace it with
a vertical transmit polarization shim.
Figure 19 shows where the shim is located and shows three of the
four Allen screws that hold the shim in place.
To replace the horizontal shim with a vertical shim, follow these
steps:
1. Obtain a vertical transmit polarization shim kit (HNS model
VTX-SHIM-KIT, P/N 1033809-0001).
Figure 20 on page 22 shows what a vertical shim looks like.
2. Loosen and remove the four Allen screws that hold the shim
in place. See Figure 19.
3. Separate the end of the waveguide from the shim.
Note: If you need to change from horizontal to vertical transmit
polarization on an antenna that has the radio assembly already
installed on the feed arm, you will have to remove the radio
assembly from the feed arm before you can follow the instructions
in this section.
Figure 19: Shim location next to TRIA
TRIA
Shim
(See also
Figure 20.)
Allen screws
(4 total)
Waveguide