Chapter 6 - TV Measuring Range
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Scan
6.2.2.1.2
You can use this function to scan the entire TV range for DVB-C signals.
For this, you must switch the instrument to channel input mode.
The scan function includes automatic detection of modulation schemes and symbol rates.
That means that the instrument scans every channel with 64QAM, 128QAM and 256QAM and the
symbol rates 6,111 kBd, 6,875 kBd and 6,900 kBd.
Figure 6-6 DVB-C select service
In this operating mode, the arrow keys have a dual function. After entry of a new channel, the menu
item
2.FUNCTION
is inverted. That means that the program list can be operated with the arrow
keys. To start the scan, first press the F5 key in order to activate the first function of the arrow keys.
The scan is then started by first tuning the measuring receiver to a channel at which the scan
should begin. Press the
↑
key to start the scan in the positive direction. Press the
↓
key to do the
same in the negative direction. When the band limit is reached, the scan continues at the other end
of the range. You can end the scan at any time by pressing
HOME
. “SCAN” is shown on the
display while the scan takes place.
DVB-C parameters
6.2.2.1.3
As soon as the receiver has completed the synchronization process, several parameters are shown
on the display. When LOCK appears, it means that the digital receiver is receiving a valid data
stream.
In contrast, UNLK means that either the quality of the signal that is present is insufficient, or that
the parameters of the receiver do not match, or that no DVB-C signal can be received at this
frequency.
Once the receiver has synchronized, the set modulation scheme and the associated symbol rate
are shown on the display.
