DRS WJ-8611, Инструкция по установке, эксплуатации и обслуживанию

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WJ-8611 DIGITAL VHF/UHF RECEIVER
3-6 LOCAL OPERATION
BEAT FREQUENCY OSCILLATOR
CONTROL
KEY
(BFO - +/- ZERO)
The BFO +/- ZERO key is selectable only when the CW detection mode is
active. It is used to introduce an offset signal into the signal path so that an
unmodulated CW type signal will produce an audible output. This is a
dual functioned key, with the numeric keypad’s SHIFT key determining
the key function.
The unshifted mode is used to select a BFO offset frequency in the range
from -8000 to +8000 Hz, in 10, 100, or 1000 Hz increments. With the CW
mode active, pressing the BFO key illuminates the key’s LED and displays
a four-digit BFO value in the parameter display. Either the 10, 100, or
1000 Hz digit flashes indicating that the BFO offset selection mode is
active and is under control of the EDIT knob. Each press of the BFO key
moves the flashing digit to change the BFO tuning resolution of the EDIT
knob. When the resolution is at the 1000 Hz digit, pressing BFO again
wraps around to the 10 Hz digit. If desired, direct BFO offset entry may
be performed by entering the desired value at the numeric key pad and
terminating the entry with the BFO key. For direct entry, the BFO Offset
must be entered with the 1 Hz digit included. The last digit entered is a
placeholder and does not affect the frequency display. The 1 Hz digit is
always zero.
In the shifted mode, the BFO key enables an operator to select between a
positive (+) offset, a negative (-) offset, or the offset may be set to ZERO
(no offset). With the CW detection mode active, and when the receiver
front panel is in the shifted mode (SHIFT LED illuminated), each press of
the BFO key toggles between these three settings. If the BFO value is
positive, the +/- ZERO function changes the polarity to negative without
affecting the absolute value of the offset. The next press zeros the offset
value, removing any BFO offset (+0000). A third press of the key sets the
BFO offset polarity to positive, and restores the original absolute value of
the offset.
SQUELCH CONTROL KEY
The SQUELCH control key sets the squelch level of the receiver. It
determines the minimum signal strength level that is required before the
receiver recognized the signals presence, and activates the audio outputs.
Typically, the squelch level is set to just above the noise level when no
signal is present. Squelch activates to disable the audio when only noise is
present. When a signal breaks the threshold, squelch is deactivated and the
audio outputs are turned on.
Courtesy of http://BlackRadios.terryo.org