Suppression Features; Using The Μ-Tune Feature - Yaesu FTDX9000D - DATA MANAGEMENT Operation Manual

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DVANCED
The FT 9000D includes an unmatched array of RF selectivity-enhancing features. Please study the material below
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carefully, so as to understand the various features complete.
The μ-Tune system is an advanced preselector for the RF front end of the Main (VFO-A) receiver, providing a much
narrower passband than the VRF circuit. The Q of the μ-Tune filter is so tight as to provide significant suppression of signals
little more than 10 kHz away from your current operating frequency, and manual adjustment of the μ-Tune filter's center
frequency allows you to position the shoulder of the filter in such a way as to enhance interference rejection to one side or
another of your current frequency. Because the insertion loss of the μ-Tune is somewhat higher than that of the VRF, we
have also provided the capability to disengage μ-Tune, and engage VRF, should your antenna and noise environment lead
to system noise figure concerns when using μ-Tune.
The FT 9000D's Main band (VFO-A) receiver is equipped with μ-Tune modules covering the 1.8 ~ 14 MHz Amateur
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bands. On the 18 ~ 50 MHz bands on the Main (VFO-A) receiver, and on all bands on the Sub (VFO-B) side, the VRF
circuit is provided.
MAIN (VFO-A) [ VRF/μ-T ] switch
µ-Tune Operation on the Main (VFO-A) Receiver
1. Press the [ VRF/µ-T ] switch. The imbedded Red LED
will light up.
The μ-Tune circuit will automatically align itself
onto your operating frequency.
Remember that μ-Tune only operates on the Main
band (VFO-A) on the 14 MHz and lower bands.
2. Now rotate the [ VRF/µ-T ] knob to peak the response
(background noise) or reduce interference.
A pictorial representation of the tuning position
of the μ-Tune filter will appear on the bar graph
on the TFT.
The amount of change in the center frequency of
the μ-Tune filter, when rotating the [ VRF/µ-T ]
knob by one click, can be configured using Menu
item "GENERAL 043 µTUNE DIAL STEP."
If you have performed manual adjustment of the
μ-Tune filter's center frequency, you may press
and hold in the [ VRF/µ-T ] key for two seconds
to re-center the filter response on your current
operating frequency.
The permeability-tuning concept utilized in the μ-Tune circuit dates back many decades, as it was incorporated in
such classic transceivers as the FT-101 and FT-901 series, in addition to the FT
Tune circuit in the FT
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transceiver.
FT 9000D O
DX PERATION
I -S
NTERFERENCE UPPRESSION
U µ-T
SING THE
MAIN (VFO-A) [ VRF/μ-T ] knob
Q Q Q Q Q
UICK UICK UICK UICK UICK
9000D is the highest development of this circuit concept ever employed in an Amateur
M
ANUAL
F
EATURES
F
UNE EATURE
μ-Tune filter will appear
on the bar graph
3. Press the [ VRF/µ-T ] 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 O TE TE TE TE TE
400 and similar models. The μ-
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: RF F E
RONT ND
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