Promax Promax TV EXPLORER HD ISDB-Tb, Manual

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USER’S MANUAL. TV EXPLORER HD ISDB-T/T
B
11/2010 Page 71
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5.16.1 Markers
( Only in Spectrum Analyser mode ). The marker in red colour indicates the central
frequency or tuning frequency, which can be moved by means of turning the rotary
selector [1] as well in channel as in frequency tuning mode [24].
When monitoring a digital signal spectrum also appears two additional markers in
white colour, which indicate the bandwidth of the digital channel (See previous Figure).
If the highlighted measurement which appears on the measurement screen
corresponds to C/N, the Spectrum Analyser mode will measure the C/N ratio at the
frequency indicated by the marker and a second marker will indicate the frequency for
the noise measurement.
5.16.2 Spectrogram.
The Spectrogram is a useful tool and it has been designed to detect problems in a
wide range of frequencies. These problems could appear at any time and sporadically.
The Spectrogram function makes a graphical representation of the frequency
signal level regards to the time. Each level is represented with a different colour, the Y-
axis belongs to frequency and the X-axis to time. Therefore a colour map is showed on
the display, see figure 46. Any frequency signal level could be displayed at any time
reference using the cursors or the variable knob. This tool is especially useful when a
level signal analysis is going to be processed during a long period of time. When the
process is finished the capture could be showed and any anomaly will be easily detected
at any time.
Figure 50.- Spectrogram.