Watkins-Johnson Company WJ-8711A, Инструкция по установке, эксплуатации и обслуживанию

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LOCAL OPERATION WJ-8711A DIGITAL HF RECEIVER
3-28
•
In any detection mode, use the noise blanker function to blank out impulsive
interference caused by sources such as automobile ignition or over the
horizon radar.
•
In AM, FM, ISB, USB, or LSB mode, use the Tunable Notch Filter to aid in
the reduction of unwanted signals outside the passband.
The following paragraphs provide details on entering the above parameters and using the
receiver enhancement features to setup the receiver in the Manual mode for optimum performance.
3.5.1
ENTERING THE TUNED FREQUENCY
In the Manual mode, the receiver monitors the frequency indicated in the FREQUENCY
display. This frequency can be any value from 0.000000 to 30.000000 MHz, at a resolution of 1 Hz. This
means that any frequency between this range can be entered. The tuned frequency can be entered and adjusted
in several ways: by the tuning wheel, the
↑
(up) and
↓
(down) keys, a numeric entry, or in the step tune mode.
The following paragraphs provide more information on using these methods to enter or adjust the tuned
frequency.
Numeric Entry:
The numeric entry keys provide for a quick means of entering a tuned
frequency. When a numeric entry key is pressed, the tuned frequency display
is erased and the value of the key pressed is displayed in the right most digit
position. Depending on the frequency being entered, all or just the most
significant digits need to be entered. For example, entering a frequency of 10
MHz only requires the following key presses:
Press 1 (the display is erased except for 1)
Press 0 (the 1 shifts left and 0 is displayed)
Press MHz (the numeric entry is terminated and the display indicates
10.000000).
The same procedure can be used for entering frequencies in the kilohertz
range by terminating the numeric entry with the kHz key. When terminating
the entry this way, the decimal point is automatically displayed and a 0 is
displayed in the 1-MHz position.
All numeric entries for tuned frequencies must be terminated with either the
kHz or MHz key. The receiver does not tune to the entered frequency until it
is terminated.
Tuning Wheel:
The tuning wheel can be used to dynamically adjust the tuned frequency
while monitoring the audio for signals. In this tuning method, the receiver is
tuning to the frequency displayed, even while the wheel is being rotated.
The tuning wheel adjusts the tuned frequency in a resolution depending on the
position of the highlighted digit in the FREQUENCY display. For example,
if the 1 kHz digit is highlighted, turning the wheel causes the value in that
position to change. When tuning up in frequency (turning the wheel
clockwise), going past 9 causes the highlighted digit to display 0 and the digit
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