Icom IC-7400 Instruction Manual page 50

4
RECEIVE AND TRANSMIT
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.
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.
• RTTY filter and twin peak filter setting
q Push [CW/RTTY] to select RTTY mode.
• After RTTY mode is selected, push [CW/RTTY] for 1 sec.
to select RTTY-R mode.
w Push [MENU] several times to select
e Push [F4
] to select RTTY menu.
r Push [F4
] to turn the RTTY filter ON and OFF.
• When the RTTY filter is turned ON, the normal IF filter
number indication (1, 2 or 3) disappears.
t Push [F4
] for 1 sec. to enter RTTY filter set
mode (see below).
y Push [F1≤] to select bandwidth item.
u Rotate the tuning dial to select the RTTY filter width
from 1 kHz, 500 Hz, 350 Hz, 300 Hz and 250 Hz.
• Push [F3] for 1 sec. to select a default value.
i Push [F2 ≥] to select twin peak filter item.
• The received audio volume may become greater when
the twin peak filter is turned ON.
o Rotate the tuning dial to turn the twin peak filter
function ON and OFF.
!0 Push [MENU] 2 times to return to
• RTTY filter set mode
1.
This item sets the RTTY filter width.
• 250, 300, 350, 500 Hz and 1 kHz can be selected.
2.
This item turns the twin peak filter ON and OFF.
37
.
RTTY filter indicator
Rotate the tuning dial to the
point where both sides of the
dots appear equally.
Disappears when the RTTY
. filter is turned OFF.
F 1 F 2 F 3
F 1 F 2 F 3
F 4 F 5
Push [F4]
F 4 F 5