Yaesu FTdx5000MP, Руководство по эксплуатации

Страница: 79 / 148

Page 77 FT
DX
5000 O
PERATING
M
ANUAL
A
DJUSTING THE
SSB T
RANSMITTED
B
ANDWIDTH
(
SSB M
ODE
)
For SSB transmission, a default bandwidth of 2.4 kHz is provided. This bandwidth provides reasonable fidelity along with
good talk power, and is typical of the bandwidth used for decades during SSB transmission. However, the bandwidth may
be varied by the operator, when preferred, to provide different levels of fidelity or increased talk power.
E
NHANCING
T
RANSMIT
S
IGNAL
Q
UALITY
Here’s how to adjust the transmitted bandwidth on SSB:
1. Press the [
MENU
] button briefly, to engage the Menu.
2. Rotate the ( VFO-A
)[
SELECT
] knob, and select Menu
item “
104 A3J TX BPF
”.
3. Rotate the (
VFO-B
)[
SELECT
] knob to select the de-
sired bandwidth. The available selections are 50-3000,
100-2900, 200-2800, 300-2700, 400-2600, and
3000WB. The default is 300-2700 Hz. A wider band-
width will provide greater fidelity, while a narrow band-
width will compress the available transmitter power
into less spectrum, resulting in more “talk power” for
DX pile-ups.
4. Press and hold in the [
MENU
] button for two seconds
to save the new setting and exit to normal operation.
A
DVICE
:
The Transmit Monitor is very helpful way of verifying
the effects on fidelity of changing the bandwidth. Press-
ing the [
MONI
] button then adjusting the [
MONI
] knob
for a comfortable listening level while you are trans-
mitting, you will be able to hear the difference in sound
quality as you make changes.
When the optional
DMU-2000
Data Management Unit
is connected, you may verify the effect of your adjust-
ments of the transmitted bandwidth by observing the
Audio Scope on the “Oscilloscope” page.
Q
UICK
P
OINTS
:
The higher fidelity associated with wide bandwidth will
be particularly enjoyable on the low bands, during lo-
cal rag-chew QSOs.
The “3000WB” setting is a special hi-fidelity setting,
whereby the transmitted bandwidth is in excess of 3
kHz. This selection, in conjunction with judicious ad-
justment of the Parametric Microphone Equalizer (see
next chapter) can provide truly outstanding fidelity and
very natural-sounding audio.
When using the wider bandwidth selections (especially
“3000WB”), the apparent power output from the trans-
mitter may seem lower. This is because the available
power from the transmitter is being distributed over a
wider bandwidth, and the power detection circuitry
does not compensate for the effect of the bandwidth
selection (it is calibrated in the default 2.4 kHz band-
width).
(VFO-B)[SELECT] Knob [MENU] Button
(VFO-A)[SELECT] Knob [MONI] Button
[MONI] Knob