Publicité
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 48.- 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 yellow 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.,.
5.15.4
DVB-S/S2 (QPSK/8PSK) signal
Go to the UTILITIES menu by pressing the
CONSTELLATION option.
The modulation type: DVB-S (QPSK) or DVB-S2 (8PSK) is showed on screen.
Next, the frequency and channel number corresponding to the channel plan selected as
well as the satellite downlink frequency. Finally, it shows the status line (similar to the
measurement screen).
Page 68
USER'S MANUAL. TV EXPLORER HD +
[22] key, and then select the
NOTE
12/2011
Publicité
