Icom IC-756PROII Marine Radio User Manual


 
37
5
RECEIVE AND TRANSMIT
Speech compressor
The RF speech compressor increases average RF
output power, improving signal strength and readabil-
ity in SSB.
Speech compressor
q Select USB or LSB mode.
w Push [COMP] momentarily to turn the speech
compressor ON and OFF.
e Push [COMP] for 1 sec. to toggle between narrow,
middle or wide transmit lter.
Transmit lter width:
NAR 2.0 kHz
MID 2.6 kHz
WIDE 2.9 kHz
Compression level setting
q Select USB or LSB mode.
w Preset the transceiver as follows:
[COMP] function : OFF
[METER] function : ALC
[MIC GAIN] control : Center position
[COMP] control : Center position
[RF POWER] control : Max. counterclockwise
e Transmit at your normal voice level.
r Adjust the [MIC GAIN] control so that the ALC
meter reads within the ALC zone, whether or not
you speak softly or loudly.
t Push [COMP] momentarily to turn the speech
compressor ON.
y Push [METER] once to select the COMP meter.
u Adjust the [COMP] control so that the COMP
meter reads within 10 dB and 20 dB.
When the ALC meter peaks above the ALC zone,
your transmitted voice may be distorted.
[METER] switch
[COMP] switch[MIC GAIN] control
[COMP] control[RF POWER] control
SWR
S
COMP
ALC
Po
0
10
10
25 50
100
20
1
0
1. 5
2
3
1
5
9
+20
+40
+60dB
dB
COMP meter
Preamp
The preamp amplifies received signals in the front
end circuit to improve the S/N ratio and sensitivity.
The transceiver has 2 preamp types.
Push [P.AMP] to select one of 2 receive RF pre-
amps or to bypass them.
•“P. AMP1 activates 10 dB preamp for HF all bands.
•“P. AMP2 activates 16 dB high-gain preamp for
24 MHz band and above.
Regarding the use of the P.AMP 2
(Pre-amplier 2)
The P.AMP 2 is a high gain receive amplier. When
the P.AMP 2 is used during times of strong electric
fields, distortion sometimes results. In such cases,
use the transceiver with the P.AMP 1 or P.AMP
OFF setting.
The P.AMP 2 is most effective when:
Used on bands above 24 MHz and when electric
elds are weak.
Receive sensitivity is insufcient during low gain, or
while using a narrow band antenna (such as small
loop, a Beverage antenna or a short Yagi antenna,
etc.) is used.
[P.AMP] switch