Labgear DAT103 Operating Manual page 14

5 – PerBER value
6 – PostBER value
7 – Erroneous packets after the Reed-Solomon decoder counter
8 – Command line with commands activated by F1, F2 and F3 keys
9 – Channel name (when working with selected channel plan)
10 – Demodulator status
11 – AMP power supply status (Section 4.3.8).
When this mode is activated or a channel is selected, the Analyzer will start the input
signal synchronization process, indicated by a progress bar in position 10. The lock icon
will appear in position 10 once synchronization is achieved. Subcarrier
modulation type and subcarrier number will be presented in position 3. Shortly thereafter
MER, Margin, preBER, postBER and damaged packet measured values will appear in
positions 4, 5, 6 and
lower than 1.0E-07, then the meter will display a «pass» message, otherwise if the errors
are too high a «fail» message will be displayed.
Digital TV Signal Quality measurements are BER and MER. An understanding of the
powerful error correction systems in every receiver are important if you are to get the best
out of your meter. This information can be found by careful Internet search or by reading
Digital TV titles at your local library.
If the signal level value of the selected channel is insufficient, a low level icon
will blink in position 10. Channel synchronization in this case is not possible. If signal level
is OK, but synchronization hasn't been achieved within 5 seconds, either in-channel
modulation impairments or high noise level from the antenna system must be
To measure channel parameters, select the required channel by ◄ and ► arrows.
If no channel plan is selected, using ◄ and ► arrows you can switch to any channel in
accordance with the selected channel template (Section 4.7). Once a signal is detected,
the Analyzer will automatically determine the channel parameters: frequency offset,
spectrum inversion, subcarriers number, subcarriers modulation type, guard interval and
code rate.
If one of the channel plans has been selected, the tuning will be performed between
the digital channels of the channel plan. In this case, after entering MER/BER mode you
will see the selected channel plan name indicated by «Plan:» for a few seconds. The
channel parameters will be taken from the channel plan. If the selected channel plan does
not include any digital channels, tuning to channels will not be performed.
NOTE! When working without a channel plan selected, the Analyzer can only
synchronize a DVB-T signal with bandwidth that matches the selected channel in the
channel template (Section 4.7)
NOTE! When working with hierarchical modulated channel, postBER is measured for
low priority stream.
When you press
synchronization again.
You can access other measurement modes using the function keys. F2 key activates
CONSTELLATION measurement mode (Section 4.3.3). F3 key opens LEVEL
measurement mode (Section 4.3.2).
7. If the preBER value is lower than 2.0E-04 and postBER value is
, measurement is interrupted and the demodulator starts channel
resolved.
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