Operation Manual

OM-E 2072-09287-00
B-4
When using the sloping dipole, pay attention to the following points:
1. Sloping dipoles exhibit mostly low-angle radiation, which is suitable for long-distance
communications, but generally poor for short-distance skywave (NVIS) operation. Sloping
dipoles are recommended for long-distance communication only.
2. The sloping dipole exhibits some gain in the direction of the sloping wire. Conversely, it
exhibits a significant null in the opposite or rear direction. This directional pattern can be used
to optimize signal strength in one favored direction, and/or minimize interference coming from
an undesired direction.
B-3.4 Wire Antenna Configuration
For extended communication ranges (on the order of hundreds of kilometers), it is strongly
recommended that a dipole antenna be used.
In emergency situations, or when the topography does not allow the erection of a dipole antenna, it is
possible to use a wire antenna. A wire antenna consists of a single conductor.
The wire antenna has a directional radiation lobe, directed in the direction at which the wire is pointed
(similar to the main radiation direction of the sloping dipole).
NOTE
The wire antenna is an improvisation when there are time or location
constraints. It is not recommended as a standard antenna.
You can also use the FAA5548 as a wire antenna by connecting only one wire to the center junction
(always to the side marked by + (plus)).
• When the wire length is close to the dipole wire length required at the operating frequency, you
can connect the wire antenna, through a coaxial cable, to the DIPOLE connector of the Micom.
In this case, select the dipole antenna upon power-up.
• When the wire length is short, connect the wire directly to the WHIP connector of the Micom.
In this case, select the whip antenna upon power up.
B-4. FAA5548 INSTALLATION PROCEDURE
CAUTION
Before installing the antenna, make sure the selected location is not
near power lines.
The procedure given below assumes familiarity with the FAA5548. For further details, refer to the
FAA5548 Tactical Dipole Antenna User Manual.
1. Whenever possible, erect poles of appropriate height to support the dipole antenna elements.
2. Attach both antenna elements to the center junction unit.
3. Connect the BNC coaxial feed line to the center junction.
4. Determine the length of the antenna elements according to the operating frequency.
5. Unwind both antenna elements until they are of the desired length, and then loop the antenna
wire through the slot on the winding spool.
6. Fully unwind the end support ropes from each winding spool. Throw the end weights over the
trees or other structures used as the end supports.
7. Pull the end support ropes until the center junction is 5 to 10 m above ground. Be sure to leave
some slack in the ropes, so that any movement of the end supports for example, as a result of
winds, will be accommodated. Tie the ropes to ensure that the antenna maintains its position.