Yaesu FC-757AT, Инструкция по эксплуатации

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FRONT PANEL CONTROLS
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CD
POWER Switch
When this switch is set to the off (out) position,
the RF INPUT jack is connected directly to the
ANT A jack, and the Tuner is removed from the
circuit. However, tuner settings (and antenna selec­
tions) stored in the memory are retained by the
internal lithium battery memory backup.
If the FC-757AT is used with a transceiver designed
to control the tuner automatically, such as the
FT-757GX or FT-980, power to the Tuner is
switched automatically via the interconnecting
control cable. In this case, the POWER switch on
the FC-757AT can be left in the on (depressed)
position, and the on/off function will be performed
by the transceiver POWER switch.
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METER Switches (SWR/PO and 15/150)
These two-position switches select the function
and full scale RF power range of the meter. In the
PO (out) position, the SWR/PO switch causes the
meter to indicate forward power output in watts,
with the 15/150 switch position determining the
related meter range.
In the SWR (depressed) position, the SWR/PO
switch activates the self-calculating SWR system,
which indicates SWR on the (lower) meter scale
when the 15/150 switch is set to the correct posi­
tion corresponding to the amount of RF power
applied from the transmitter (if at least 10- 15
watts).
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SENSitivity Control
This potentiometer adjusts the SWR threshold level
at which the automatic tuning system automatical­
ly starts and stops its tuning procedure. If the SWR
of the antenna system is close to 1. 5: 1, this control
should be set fully clockwise for
maximum
sensitivity to SWR. However, if the SWR is high,
the SWR null may be too sharp for the automatic
sensing circuitry to notice, in which case the SENS
control must be set further counterclockwise.
For manual tuning and mobile operation or other
conditions where the SWR continually fluctuates,
the SENS control should be set fully counterclock­
wise. Also, once auto-tuning has been completed
and the tuner settings are to be retained in
memory, set this control fully counterclockwise.
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ANTENNA Buttons
These five momentary contact buttons are used to
select antennas. The first button (A) at the left will
select the ANT A jack on the rear panel. This is
also the default condition, and thus this selection
is made automatically while power is off.
Ordinarily, any of the four remaining buttons will
select the antenna connected to the ANT B jack
on the rear panel. However, when the FC-757AT
is used with the FAS-l -4R Remote Antenna
Selector, each of these buttons will select, via the
interconnecting control cable, one of the four jacks
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