Promax PROLINK-3 Premium Manual De Instrucciones página 169

USER'S MANUAL. PROLINK-3/3C
The graph always locates the signal of maximum amplitude in t=0, and shows to
the different echoes analysing an approximated time interval of 200 µs (see the
attached table).
PRE-ECHO
BW
Time
20 µs
6 MHz
23 µs
7 MHz
26,25 µs
8 MHz
NOTE: When an echo or a pre-echo from a delay surpasses the margins defined in the
previous table, the equipment will not be able to discern which type of reflexion
has ocurred and it could appear represented, due to a cyclical scroll, in the
opposite side of the graph.
First, appears on the screen the computing time percentage for the acquisition in
progress.
Turn the rotary selector [4] to analyse the signal echoes that have been registered
in the acquisition. For example in the following figure at 70 µs of the reference signal
appears an echo of a level of — 25,2 dB with respect to the main signal. Between
parenthesis an estimation of the difference of routes (20.9 km) between the signals that
originate the echo and as well as the dynamic margin of the analysis (10 dB/div) is
indicated.
Figure 20b.- DVB-T COFDM signal impulsive response.
06/2005
Premium
ECHO
Time
148 µs
173 µs
197,75 µs
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