Yaesu FT-950 Operating Manual page 45

μ-T
UNE
A :
DVICE
The μ-Tune filters are the most advanced, selective RF preselector filters ever incorporated into an Amateur Radio
transceiver. The RF selectivity provided by μ-Tune can be of tremendous value in ensuring quiet, intermod-free recep-
tion even in the most crowded bands on a contest weekend. The μ-Tune filters provide RF selectivity on the order of a
few dozen kHz at -6 dB, at the expense of a few dB of system gain on bands where noise figure is seldom an issue. You
will notice that the S-meter deflection, when μ-Tune is engaged, is slightly less than when it is out of the circuit; this is
normal. If your antenna system gain is so low that you cannot hear the band noise when μ-Tune is engaged (highly
unlikely), just switch it out, to eliminate the slight insertion loss.
As you tune around on an amateur band with μ-Tune engaged, the microprocessor automatically commands the stepper
motor driving the toroid core stack to center the filter on your current operating frequency. You may, however, use the
[ SELECT ( μ-TUNE )] knob to skew the filter response to one side or the other from your operating frequency, to deal
with heavy interference on one side. To re-center the μ-Tune filter on your operating frequency, and eliminate any
offset, press the [ CLEAR ] button.
Q N :
UICK OTE
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, the FT-901 series, the FT
circuit as our flag ship model the FT
Amateur transceiver.
1. Press the [ MENU ] button to engage the Menu
mode.
2. Rotate the [ SELECT ] knob to select Menu item
"006 DISP BARSEL
006 DISP BARSEL 006 DISP BARSEL". 006 DISP BARSEL 006 DISP BARSEL
A :
DVICE
Press the [ SELECT ] knob to toggle the Menu item
display between "006 DISP 006 DISP" and "BARSEL
006 DISP 006 DISP
006 DISP
3. Rotate the [ CLAR/VFO-B ] knob to select "u-tn
(μ-Tune)" (replacing the default "C-tn
ING)" selection).
4. Press and hold in the [ MENU ] button for one sec-
ond to lock in the new setting and exit to normal
operation.
FT-950 O
PERATING
I
( R
F
ILTER EQUIRES THE OPTIONAL
9000, which is the highest development of this circuit concept ever employed in an
DX
Changing the Tuning Offset Indicator
BARSEL BARSEL BARSEL".
BARSEL
u-tn u-tn u-tn
u-tn
C-tn (CW TUN-
C-tn C-tn
C-tn
M
ANUAL
NTERFERENCE
RF μT
400, and similar models. The μ-Tuning Kit uses the same
DX
[ SELECT ] Knob
R
EJECTION
)
K
UNING IT
[ MENU ] Button [ CLAR/VFO-B ] Knob
Page 43