D About Rtty Reverse Mode; D Rtty Filter/Twin Peak Filter - Icom IC-756PROIII Instruction Manual

4
RECEIVE AND TRANSMIT
D D About 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.
Normal
170 Hz 2125 Hz
Space Mark
BFO
D D RTTY filter/Twin peak filter
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. 47)
Moreover, the twin peak filter changes the receive fre-
quency response by boosting 2 particular frequencies
for better copying of desired RTTY
(2125 and 2295 Hz)
signals.
[RTTY FIL] [CW/RTTY]
BW BW 350 350
SFT SFT
ANT ANT
1
T X T X VFO VFO
qr.qpp.pp
METER METER
Po Po
1
45
Reverse
2125 Hz 170 Hz
Space Mark
BFO
[EXIT/SET]
TPF indicator
qw:pp
0
TPF TPF
12:00 12:00
R T T Y R T T Y FIL2 FIL2
21.076.50 21.076.50 CW CW
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.
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 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 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.