Publicité
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.
To access the spectrogram, first press the button
analyser. Then you should set the parameters reference, span and frequency. Then
press
[22] and select SPECTROGRAM using the cursors or the variable knob. The
figure below shows the initial screen.
Page 72
USER'S MANUAL. TV EXPLORER HD +
Figure 52.- Spectrogram.
[13] to access the spectrum
12/2011
Publicité
