Yaesu FT DX 9000MP CONTEST - DATA MANAGEMENT..., Руководство по эксплуатации

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Page 69 FT
DX
9000MP O
PERATION
M
ANUAL
IIIII
NTERFERENCE NTERFERENCE
NTERFERENCE NTERFERENCE NTERFERENCE
R R R R R
EJECTION EJECTION
EJECTION EJECTION EJECTION
(S(S(S(S(S
IGN IGN
IGN IGN
IGNALS ALS
ALS ALS
ALS
O O O O O
FF FFFF
FFFF
F F F F F
REQ REQ
REQ REQ
REQUENCY UENCY
UENCY UENCY
UENCY BY BY
BY BY
BY
J J J J J
UST UST
UST UST
UST AAAAA
F F F F F
EW EW
EW EW
EW KHZ KHZ
KHZ KHZ
KHZ
)))))
R.FLT
(
R
OOFING
F
ILTERS
)
Narrow-band Roofing Filters of 15 kHz, 6 kHz, and 3 kHz bandwidths are provided in the first IF, right after the first mixer.
These filters provide protection for the 2nd mixer, DSP, and other circuitry that follow, and can dramatically improve
reception on a very crowded band (during a contest, etc.). Typically, the AUTO selection mode is satisfactory for most
operating situations, but in an extremely crowded phone band you may wish to select, for example, the 3 kHz roofing filter
for SSB operation.
M
AIN
B
AND
(VFO-A) R
OOFING
F
ILTER
O
PERATION
Press the Main (VFO-A) band’s [ ROOFING
] switch
to toggle the Roofing Filter selection.
AUTO 15kHz 6kHz 3kHz AUTO
As you repeatedly press this switch, you will ob-
serve different LEDs lighting up in the Roofing Fil-
ter area of the front panel, denoting the Roofing Fil-
ter currently in use. Also, the selected Roofing Filter
bandwidth will be indicated on the LCD display.
Typically, this selection will be set to “AUTO.”
The Roofing Filter selection will be memorized
independently on each VFO in the VFO stack.
S
UB
B
AND
(VFO-B) R
OOFING
F
ILTER
O
PERATION
1. Pressing the Sub (VFO-B) band’s [ RX
] switch will
engage Dual Receive operation.
When the imbedded LED grows green, this is your
confirmation that Dual Receive is in operation.
2. Press the Sub (VFO-B) band’s [ FLT
] switch to toggle
the Roofing Filter selection.
AUTO
15kHz 6kHz 3kHz AUTO
As you repeatedly press the [ FLT
] switch, the se-
lected bandwidth will appear on the LCD display.
Typically, this selection will be set to “AUTO.”
When “AUTO” is selected, the LED imbedded in
the switch will go out (there always is a roofing
filter in the receiver path).
The Roofing Filter selection will be memorized
independently on each VFO in the VFO stack.
MAIN(VFO-A)
[ROOFING] Switch
Roofing Filter bandwidth will be indicated on the LCD
SUB(VFO-b)
[R.FLT] Switch
Q Q
Q Q Q
UICK UICK UICK UICK UICK
P P
P P P
OINT OINT OINT OINT OINT
The “AUTO” selection of the Roofing Filter is
based on the operating mode. However, you
may override the automatic selection, if band
conditions warrant a different (usually, a tighter)
selection.
The AUTO mode Roofing Filter selections are
shown below:
AM/FM/FM-PKT 15kHz
LSB/USB/PKT 6kHz
CW/RTTY 3kHz
VDD TEMP SWR BIAS
Roofing Filter bandwidth will be
indicated on the LCD
T T
T T T
ERMINOL ERMINOL ERMINOL ERMINOL ERMINOLOGY OGY OGY OGY OGY
A “Roofing Filter,” as its name implies, places a
“Roof” over the receiver’s IF system bandwidth.
This “Roof” protects the circuitry downstream from
the first mixer from interference, just as a roof on a
house protects the contents from rain and snow.