Promax SKYHUNTER Manual De Instrucciones página 51

USER'S MANUAL SKYHUNTER.
Active function Measured value
indicator of the LNB voltage
Signal value
in dBµV
The top line of the screen shows the measured LNB voltage and whether the 22
kHz are present (see figure 15). It also shows whether a signal with valid transport
stream is detected at the frequency (or frequencies) assigned to a specific satellite (in
which case 'mer' or 'MER' appears on screen).
The bottom line of the screen shows simultaneously the power level, the channel bit
error rate, and the modulation error ratio measurements. Each data appears over its
respective field located below the screen (POWER), (CBER) and (MER)
Note: For the final step of precise adjustment and signal quality optimisation, it is
important to select the test point where the signal is at its most critical. This
guarantees the quality of the other points with more favourable conditions.
If a signal with a valid transport stream presents a modulation error ratio (MER)
greater than the value internally defined by the instrument as the threshold for a good
quality signal, then the screen shows the message 'MER'. Otherwise, if the value is
below this threshold, the screen will show the message 'mer'. The instrument is
delivered already configured with a quality threshold of 5 dB. This value corresponds to
the DVB recommendation for a CODE RATE = 3/4. Nevertheless, the user can alter
this value to adapt it to his own quality specification. (see section '4.3 Instrument
Configuration').
If, on moving the antenna, the signal noise ratio value exceeds the quality
reference, then the instrument will emit a high-pitched acoustic signal. On the other
hand, if the value is below the quality reference then the instrument emits a low-pitched
signal.
If you wish to measure the signal/noise ratio for other satellites memorised by the
instrument and you know that the antenna is correctly oriented, you can change
satellites by pressing key
07/2006
22 kHz signal
The signal is applied
The signal is not applied
CBER value MER value
in dB
Figure 15.- Measuring MER.
[3] until you have selected the right one.
Signal indication
No signal with a valid transport
stream detected
mer: Valid signal with a MER
smaller than that defined
as threshold
MER: Valid signal with a MER
greater than that defined
as threshold
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