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In the C/N mode the carrier to noise ratio of the tuned channel or
frequency is displayed. The C/N measurement bandwidth and the
frequency offset for the noise measurement may be controlled from
the screen. A proprietary DSP technique allows C/N measurements
on modulated carriers (non-scrambled channels). The measurement
is made by measuring the video carrier level and then tuning to the
offset frequency, searches for a quiet line. Once a quiet line is found,
the unit will then measure four consecutive frames and average the
values together. The value is then corrected for the selected band-
width, and the C/N ratio is computed.
Information displayed in the C/N mode is as follows:
• Channel number
• Channel label
• Carrier frequency
• Noise offset frequency
• Noise frequency
• Bandwidth
• C/N ratio
• Channel plan
• Battery status
To make a carrier to noise measurement, press the
C/N
key. The
C/N ratio of the tuned channel or frequency will be displayed.
Summary of Contents for 3SR
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