USER'S MANUAL. TV EXPLORER II/II+
5.15.2 DVB-C (QAM) signal
Sets on the UTILITIES menu by pressing the
CONSTELLATION option.
On screen appears the modulation type: DVB-C (256 QAM). Also the frequency
and channel number are indicated. Finally, it shows the type of DVB-C broadcast
network used.
Figure 43.- Constellation diagram. DVB-C (QAM 256) signal.
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.,.
5.15.3
DVB-S/S2 (QPSK/8PSK) signal
Go to the UTILITIES menu by pressing the
CONSTELLATION option.
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[22] key, and select the
NOTE
[22] key, and then select the
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