Icom IC-756PROII Marine Radio User Manual


 
28
5
RECEIVE AND TRANSMIT
The transceiver has 5 RTTY lters in addition to nor-
mal IF filters. The passband width can be selected
from 1 kHz, 500 Hz, 350 Hz, 300 Hz and 250 Hz.
When the RTTY lter is turned ON, the RTTY tuning
meter can be used. (p. 42)
Moreover, the twin peak lter changes the receive fre-
quency response by boosting 2 particular frequencies
(2125 and 2295 Hz) for better copying of desired RTTY
signals.
q Push [CW/RTTY] once or twice to select RTTY
mode.
w Push [RTTY FIL] to turn the RTTY lter ON.
•“TPF appears when the twin peak lter is turned ON.
RTTY lter selection
q Push [EXIT/SET] several times to close a multi-
function screen, if necessary.
w Select RTTY mode.
e Push [RTTY FIL] for 1 sec. to enter RTTY lter set
mode.
r Push [(F-1)Y] to select band width item.
t Rotate the tuning dial to select the RTTY filter
width from 1 kHz, 500 Hz, 350 Hz, 300 Hz and
250 Hz.
Push [(F-3)DEF] for 1 sec. to select a default value.
y Push [(F-2)Z] to select twin peak lter item.
The received audio volume may become greater when
the twin peak lter is turned ON.
u Rotate the tuning dial to turn the twin peak filter
function ON or OFF.
i Push [EXIT/SET] to exit the RTTY lter set mode.
BWBW
350350
SFTSFT
0
VFOVFO
FIL2FIL2
RTTYRTTY
qw:pp
TXTX
1
CWCW
qr.qpp.pp
21.076.5021.076.50
TPFTPF
METERMETER
PoPo
ANTANT
1
[RTTY FIL]
[CW/RTTY]
TPF indicator
RTTY reverse mode
Received characters are occasionally garbled when
the receive signal is reversed between MARK and
SPACE. This reversal can be caused by incorrect
TNC connections, settings, commands, etc.
To receive a reversed RTTY signal correctly, select
RTTY-R (RTTY Reverse) mode.
q Push [CW/RTTY] once or twice to select RTTY
mode.
w Push [CW/RTTY] for 1 sec. to select RTTY or
RTTY-R mode.
Check the receive signal.
RTTY lter/Twin peak lter
CW reverse mode
CW-R (CW Reverse) mode receives CW signals with
a reverse side CW carrier point like that of LSB and
USB modes.
Use when interfering signals are near a desired signal
and you want to change the interference tone.
q Push [CW/RTTY] once or twice to select CW
mode.
w Push [CW/RTTY] for 1 sec. to select CW or CW-R
mode.
Check the interfering tone.
Push for 1 sec.
BFO
CW-R mode (USB side)
BFO
Desired signal
CW mode (LSB side)
Interference
Desired signalInterference
CW/RTTY