Installing Lightning Protection; Installing Your Antenna System - Icom IC-703 Instruction Manual

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-703 is your first radio or one of
many, one of your key elements in a great shack is
the antenna system. There is a connection on the
back of your IC-703, for HF and 6 m. If you are using
one antenna for HF and 6 m, for simplicity, connect
the antenna coax to ANT.
ANTENNA
Connect a HF/50MHz antenna
Impedance: 50Ω
Your IC-703 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.
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-703 has an SWR meter to
monitor the antenna SWR continuously.
QUICK REFERENCE GUIDE
NOTE: There are many publications covering
proper lightning protection, check with your local
dealer for more information and recommendations.
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-703
with this type of antenna.
CAUTION: Although your IC-703 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
solder 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
II