READ THIS INSTRUCTION MANUAL CAREFULLY
before attempting to operate the transceiver.
SAVE THIS INSTRUCTION MANUAL—This manual
contains important safety and operating instructions for
the IC-746.
PRECAUTIONS
RWARNING! HIGH VOLTAGE! NEVER attach an
antenna or internal antenna connector during trans-
mission. This may result in an electric shock or burn.
RNEVER apply AC to the [DC13.8V] socket on the
transceiver rear panel. This could cause a fire or ruin
the transceiver.
RNEVER apply more than 16 V DC, such as a 24 V
battery, to the [DC13.8V] socket on the transceiver rear
panel. This could cause a fire or ruin the transceiver.
RNEVER let metal, wire or other objects touch any in-
ternal part or connectors on the rear panel of the trans-
ceiver.This may result in an electric shock.
NEVER allow children to play with equipment contain-
ing a radio transmitter.
NEVER expose the transceiver to rain, snow or any liq-
uids.
AVOID using or placing the transceiver in areas with
temperatures below –10°C (+14°F) or above +60°C
(+140°F). Be aware that temperatures on a vehicle’s
dashboard can exceed 80°C (+176°F), resulting in per-
manent damage to the transceiver if left there for ex-
tended periods.
AVOID placing the transceiver in excessively dusty en-
vironments or in direct sunlight.
AVOID placing the transceiver against walls or putting
anything on top of the transceiver. This will obstruct
heat dissipation.
During mobile operation, DO NOT operate the trans-
ceiver without running the vehicle’s engine. When
transceiver power is ON and your vehicle’s engine is
OFF, the vehicle’s battery will soon become exhausted.
Make sure the transceiver power is OFF before start-
ing the vehicle. This will avoid possible damage to the
transceiver by ignition voltage spikes.
During maritime mobile operation, keep the transceiver
and microphone as far away as possible from the mag-
netic navigation compass to prevent erroneous indica-
tions.
BE CAREFUL! The heatsink will become hot when op-
erating the transceiver continuously for long periods.
BE CAREFUL! If a linear amplifier is connected, set
the transceiver’s RF output power to less than the lin-
ear amplifier’s maximum input level, otherwise, the lin-
ear amplifier will be damaged.
Use Icom microphones only (supplied or optional).
Other manufacturer’s microphones have different pin
assignments and connection to the IC-746 may dam-
age the transceiver.
EXPLICIT DEFINITIONS
The explicit definitions described below apply to this in-
struction manual.
BUILT-IN DSP
The IC-746’s DSP digitally transposes receive audio
components in all modes of operation to produce de-
sired AF frequency characteristics at the IF stage of
the transceiver. DSP provides the following functions:
➩ Noise reduction—reduces various types of noise
and enhances receive signal components only.
➩
Automatic notch filter—automatically reduces single
beat interference and protects the receive voice signals.
➩ Selectable APF—a total of 3 passband widths are
selectable (80/160/320 Hz), for super-narrow filter
APF functions in CW mode. The APF center fre-
quency is adjustable.
