Furuno FAX-408 - Manual (Page 33)

3. INSTALLATION
23
3.2.2 Whip or wire antenna
• Either a long wire or whip antenna may be used. A wire antenna should be 10 meters or longer
including the vertical section. A whip antenna should be 6 meters long. Generally a whip
antenna is suitable for reception over 6 MHz and wire antenna is suitable for reception under 6
MHz.
• The antenna can be shared with other receivers; use an antenna switch.
• If, when using a wire antenna, sensitivity is low, install the preamp unit (option).
3.2.3 Installation of optional preamp unit (FAX-5)
Small boats may not afford the space to install a long wire
antenna. In this case it is recommended to install the preamp
unit with 2.6 meter whip antenna. The preamp unit can be
installed two ways:
• The base of the preamp unit is designed to accept a
threaded extension of one-inch diameter. The pitch of the
thread should be 14 threads per inch. The mast itself
should be no longer than 1.5 meters to prevent flexing in
heavy winds.
• Attach the preamp unit to a mounting post with stainless
steel hose clamps (option).
Mounting
1. Fix the preamp unit to the mounting location.
2. Screw the whip antenna onto the preamp unit.
3. If the mast is metallic, run a ground wire (local supply)
between the mast and the ground terminal on the preamp
unit.
4. Waterproof the junction and other exposed metallic parts
with silicone sealant.
5. Connect its coaxial cable directly to the antenna con-
nector on the FAX-408. Note that an extension cable kit
(option) is available, in lengths of 10, 20, 30, 40 and 50 m.
Note 1: A wire antenna several meters in length can be connected instead of the whip antenna.
In this case, install the wire antenna fixture (supplied with preamp unit) between the antenna wire
and the preamp unit as illustrated above.
Note 2: The preamp unit is powered by the facsimile receiver. To power the preamp unit, turn on
the Switch S1 on the RCV board in the main unit. See page 24 for the location of the DIP switch.
50
Thread
(14 threads/inch)
Inch Pipe
2.6 m Whip
Antenna
Spring
Washer
Post Hose
Clamp
(option)
Ground
Spot
Antenna Wire
Screw
Wire Antenna
Fixture
Preamp Unit
INCH PIPE
HOSE CLAMP (option) ON POST
WIRE ANTENNA