28
5
RECEIVE AND TRANSMIT
The transceiver has 5 RTTY filters 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 filter is turned ON, the RTTY tuning
meter can be used. (p. 42)
Moreover, the twin peak filter 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 filter ON.
• “TPF” appears when the twin peak filter is turned ON.
• RTTY filter 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 filter 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 filter item.
• The received audio volume may become greater when
the twin peak filter 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 filter set mode.
BW
BW
350
350
SFT
SFT
0
VFO
VFO
FIL2
FIL2
R T T Y
R T T Y
qw
:
pp
TX
TX
1
CW
CW
qr.qpp.pp
21.076.50
21.076.50
TPF
TPF
METER
METER
Po
Po
ANT
ANT
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 filter/Twin peak filter
■
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 signal
Interference
CW/RTTY
IC-756PROII.qxd 02.1.8 15:51 Page 28