Icom IC-725 Instruction Manual

PRE-OPERATION
4
4-5
TRANSMITTER CONTROLS
AND SWITCH
TRANSMIT/ALC
INDICATOR
Lights up
when
transmitting.
Lighting
intensity
depends
on the mic
gain
and
your
voice
level.
See
MIC GAIN
control
information
below.
SPLIT SWITCH
For transmitting on
one frequency and receiving
on
another.
See
detailed information on
p.
21.
RF
POWER
CONTROL
Varies the RF output power
from
10
W to maximum.
Adjust this control for the desired output power
level.
Maximum output
power
•SSB
:
100
W PEP
•
CW,
FM
: 100 W
•
AM :
40 W
(AM and FM
operations
require the
optional UI-7 AM
•
FM
UNIT.)
MIC
GAIN
Used
for adjusting the mic gain.
Adjust this control
to
the
point where the ALC
indicator lights up
at
its brightest
level
while speaking into
the
mic
using your normal
voice level.
See
ALC
INDICATOR information
above.
Tech
Talk from
Icom
Q:
What
is ALC?
A: ALC means Automatic Level
Control.
The ALC
circuit limits output power by
controlling the input
level
of the RF power amplifier.
The RF power amplifier
is
designed
as a
linear
ajnplifier
to amplify
an input signal proportionally.
The linear
amplifier
functions
in the
linear
area
of
the
signal.
However,
if the input
signal
level
exceeds
the
limit
of
linearity, the
linear
amplifier
outputs
distorted
signals
because
the
signal is
amplified in
a
non-linear
area of
the signal.
To
prevent
transmitting
distorted
signals, the ALC
circuit detects a
signal
and applies
it to a
driver
amplifier as
feedback to
reduce
driver output
power.
Therefore,
the
input signal
level to
the
RF
power
amplifier is
reduced
and
the
transceiver
transmits
clear
signals.

Icom IC-725 Specifications

General

Brand	Icom
Model	IC-725
Category	Transceiver
Language	English