Icom IC-7400 Instruction Manual page 5

3. Installing lightning protection
Although you may not live in an area with high occur-
rence for lightning storms, it is always wise to take
precautions for lightning or static discharges. Proper
lightning protection not only offers protection to the
ham gear, but the shack and most importantly the op-
erator.
4. Installing your antenna system
Whether your IC-7400 is your first radio or one of
many, one of your key elements in a great shack is
the antenna system. There are three connections on
the back of your IC-7400, two for HF and 6 m and one
for 2 m. If you are using one antenna for HF and 6 m,
for simplicity, connect the antenna coax to ANT 1.
ANTENNA 1, 2
[Example]: ANT1 for 1.8–18 MHz bands
ANT2 for 21–50 MHz bands
144 MHz ANTENNA
Your IC-7400 is equipped with an internal antenna
tuner (ATU) for operation on 160–6 m. This ATU is de-
signed to work with an unbalanced 50 Ω feedline. The
purpose of the internal antenna tuner is to match the
impedance of your antenna system to as close to a
50 Ω load as possible. This ATU will not operate with
a long wire or ladder line (450 Ω or other balanced
feedlines). An external ATU such as the AH-4 would
be necessary for this kind of operation.
Connect a VHF (60–144 MHz)
antenna; impedance: 50 Ω.
QUICK REFERENCE GUIDE
NOTE: There are many publications covering
proper lightning protection, check with your local
dealer for more information and recommendations.
Antenna SWR
Each antenna is tuned for a specified frequency
range and SWR may be increased out-of-range.
When the SWR is higher than approx. 2.0:1, the
transceiver's power drops to protect the final tran-
sistors. In this case, an antenna tuner is useful to
match the transceiver and antenna. Low SWR al-
lows full power for transmitting even when using the
antenna tuner. The IC-7400 has an SWR meter to
monitor the antenna SWR continuously.
PL-259 CONNECTOR INSTALLATION EXAMPLE
q
30 mm
Coupling ring 10 mm (soft solder)
w
10 mm
Soft
solder
1–2 mm
solder solder
e
r
30 mm ≈ in 10 mm ≈
9
⁄
8
R WARNING: Although a mag mount antenna
works great on a vehicle, DO NOT use the IC-7400
with this type of antenna.
CAUTION: Although your IC-7400 has protection
to drop down power with a high SWR, this does not
completely protect the transceiver from transmis-
sion without an antenna. Make sure you have an
antenna connected whenever you transmit with
your radio.
NOTE: There are many publications covering
proper antennas and their installation, check with
your local dealer for more information and recom-
mendations.
Slide the coupling ring
down. Strip the cable
jacket and soft solder.
Strip the cable as
shown at left. Soft sol-
der the center con-
ductor.
Slide the connector
body on and solder it.
Screw the coupling
ring onto the
connector body.
in 1–2 mm ≈
3 1
⁄ ⁄ in
8 16
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