Icom IC-756 Marine Radio User Manual


 
34
4
RECEIVE AND TRANSMIT
The transceiver has 3 transmit meter functions for
your convenience. Select the desired meter with the
[METER] switch.
Push [METER] to select RF power (Po), SWR or
ALC for transmit metering.
Meter function
The RF speech compressor increases average RF
output power, improving signal strength and readabil-
ity in SSB.
q Select USB or LSB mode.
w Preset the transceiver as follows:
[COMP] function : OFF
[METER] function : ALC
[RF POWER] control : Max. counterclockwise
e Adjust the [MIC GAIN].
- While transmitting at your normal voice level, the ALC
meter should read at about the middle of the ALC
zone.
r Push [COMP] to turn the speech compressor ON.
t Adjust the [COMP] control so that the ALC meter
reads within the ALC zone whether you speak
softly or loudly.
When the ALC meter peaks above the ALC zone,
your transmitted voice may be distorted.
Speech compressor
The SWR meter indicates the SWR over the trans-
mission line in all modes.
q Push [TUNER] to turn the antenna tuner OFF.
w Push [METER] to select the Po meter.
e Push [RTTY] to select RTTY mode.
r Push [TRANSMIT].
t Rotate [RF POWER] clockwise past the 12 oclock
position for more than 30 W output power (30%).
y Set transmit meter to the SWR meter.
u Read the SWR on the SWR meter.
The built-in antenna tuner matches the transmitter
to the antenna when the SWR is lower than 3 : 1.
SWR reading
[METER] switch
S
Po
0
10
1
1
1.5
2
3
5
9
+20
+40
+60dB
25
50
100
SWR
ALC
ALC meter
S
Po
0
10
1
1
1.5
2
3
5
9
+20
+40
+60dB
25
50
100
SWR
ALC
SWR meter
Less than 1.5:1
[METER] switch
[COMP] switch[MIC GAIN] control
[COMP] control[RF POWER] control
DISPLAY
INDICATION
MEASUREMENT
Po
Indicates the relative RF output power in
%.
SWR
Indicates the SWR over the transmission
line.
ALC
Indicates the ALC level. When the meter
movement shows the input signal level
exceeds the allowable level, the ALC limits
the RF power. In such cases, reduce the
[MIC GAIN] control.