Yaesu FTDX-9000MP, Руководство по эксплуатации

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Page 166 FT
DX
9000MP O
PERATION
M
ANUAL
RF μ -T RF μ -T
RF μ -T RF μ -T
RF μ -T
UNING UNING
UNING UNING
UNING
U U U U U
NITS NITS
NITS NITS
NITS
(((((MTU-160, MTU-80/40, MTU-30/20 MTU-160, MTU-80/40, MTU-30/20
MTU-160, MTU-80/40, MTU-30/20 MTU-160, MTU-80/40, MTU-30/20 MTU-160, MTU-80/40, MTU-30/20)))))
The optional RF μ -Tuning Units provide ultra-sharp RF selectivity for the Main (VFO-A) band. The high Q is made
possible by the narrow-band design; one μ -Tune module is required for the 1.8 MHz band ( MTU-160 ), while the 3.5 and
7 MHz bands are covered by the
MTU-80/40
, and the 10.1 and 14 MHz bands are covered by the
MTU-30/20
.
When one of three optional units is installed, it will automatically be adjusted so as to center on your operating frequency.
The narrow bandwidth is especially useful on the low bands, where many strong signals being received via NVIS propaga-
tion (Near Vertical-Incidence Signals) within a narrow bandwidth, and the added protection at the RF stage is especially
helpful in preventing IMD and blocking.
The μ -Tuning circuitry, with a Q and shape factor much higher than that afforded even by VRF, can also be manually
adjusted to provide relief against interference as close as 10 kHz away. The insertion loss of the μ -Tune filters is higher than
that of the VRF circuit, so if Noise Figure is a concern you may select the VRF circuit, instead of μ -Tuning, via the Menu.
μ -T
UNE
O
PERATION ON THE
M
AIN BAND
(VFO-A) R
ECEIVER
1. Press the [
VRF/ μ
] switch. The imbedded Red LED
will light up.
P
The μ -Tune circuit will automatically align itself
onto your operating frequency.
P
Remember that μ -Tune only operates on the VFO-
A band on the 14 MHz and lower bands.
2. Now rotate the [
VRF/ μ
] knob to peak the response
(background noise) or reduce interference.
P
The amount of change in the center frequency of
the
μ -Tune filter, when rotating the [ VRF/ μ
] knob
by one click, can be configured using Menu item
“
GENERAL 042 μ TUNE DIAL STEP ”.
3. Press the [
VRF/ μ
] switch (momentarily) once more
to disengage the μ -Tune filter; the imbedded Red LED
will switch off. In this mode, only the fixed bandpass
filter for the current band will be engaged.
N N
N N
N
O O O O OTE TE TE TE TE
The μ -Tuning modules are available only for the
Main band (VFO-A), and only function up through
the 14 MHz band. On the 18 MHz and higher Ama-
teur bands, the VRF circuitry is utilized.
[VRF/ μ ] Knob
[MCH-GRP] Switch
VDD TEMP SWR BIAS
[MCH-GRP] Switch