The transmission quality is visualised in a qualitative way using a colour range for
the symbol density concentrated in a certain area. This colour coding goes from
black (no symbols) to red (maximum density), and runs from blue to yelllow in
ascending order.
A greater dispersion of the symbols indicates greater level of noise or worse signal
quality.
If concentration of symbols or noise appears is indicative of good carrier/noise ratio
or absence of problems as phase noise, etc.,.
5.16
Spectrum Analyser
The Spectrum Analyser mode allows the user to discover the signals present in
the frequency band in quickly and easily and to make measurements at the same time.
To select it press
the next figure.
The horizontal lines define the signal level, the broken lines being separated a
distance equals to 10 dB. The level of the top line (70 dBµV in previous figure), named
Reference Level, can be altered using the vertical cursors
60 dBµV to 130 dBµV by steps (from 70 dBµV to 130 dBµV in satellite band). The vertical
measurement range changes to 5 dB/div by holding pressed the lower arrow cursor key
[6] and changes to 10 dB/div by holding pressed the upper arrow cursor key
Page 66
[13] key. The monitor will show a picture like the one described in
Figure 46.- Spectrum analyser mode.
USER'S MANUAL. TV EXPLORER HD / HD
[6] key over a range from
LE
NOTE
[6].
05/2011