Page 69
FT-
991
Operating Manual
Enhancing Transmit Signal Quality
Adjusting the SSB Transmitted Bandwidth
(
SSB Mode
)
For SSB transmission, a default bandwidth of 2.4 kHz is available. This bandwidth provides reasonable fidelity along
with good talk power, and is the typical bandwidth used for decades for SSB transmission. The transmit bandwidth may
be varied by the operator, to provide different levels of fidelity or talk power, according to individual preferences.
Here are the steps to adjust the SSB transmit bandwidth:
1. Press the
MENU(SETUP)
button to engage the
Menu.
2. Rotate the
MULTI
knob to select Menu item “
110
SSB TX BPF
”.
3. Touch [
SELECT
] on the TFT display, then rotate
the
MULTI
knob to select the desired bandwidth.
The available selections are: 100-3000 Hz, 100-
2900 Hz, 200-2800 Hz, 300-2700 Hz, 400-2600 Hz.
The default is 300-2700 Hz. A wider bandwidth will
provide greater fidelity. A narrow bandwidth will
compress the available transmitter power into less
spectrum, resulting in more “talk power” for DX
pile-ups.
#
#2( 9+ 6
& *
&+7/
55$ 6: $ (
2
55
2 4
1
'
6 5 .'%6
#
/'
$
4. Touch [
ENTER
] on the TFT display to save the new
setting.
#
#2( 9+ 6
& *
&+7/
55$ 6: $ (
2
55
2 4
1
5
6
'.'%6
#
/'
$
5. Press the
MENU(SETUP)
button or touch [
BACK
]
on the TFT display to exit to normal operation.
Advice:
The Transmit Monitor function is a very helpful way to
confirm the effect that changing the bandwidth will have
on fidelity. To activate the Monitor function, press the
F
(MLIST)
button to reveal the functions list on the TFT
LCD display. Then touch the [
MONI
] button, you will
be able to hear the difference in sound quality as you
make bandwidth changes.
Quick Points:
The higher fidelity associated with wide bandwidth will
be particularly enjoyable on the low bands during local
rag-chew QSOs.
MULTI Knob
MENU(SETUP) Button
F(M-LIST) Button
