Important Remark; Measuring The Power Of Digital Channels (Channel Power) - Promax PROLINK-3 Premium Manual De Instrucciones

USER'S MANUAL. PROLINK-3/3C
Figure 8.- Carrier-to-noise ratio measurement (Auto mode).
As well as the video carrier / noise level ratio (20.1 dB in previous figure), the
frequency or channel (depending on the tuning mode selected) and the level of the
video carrier and noise level are also shown.
When measuring channels in the satellite band or digital channels, to measure
the C/N ratio correctly, the bandwidth of the channel must be defined previously, using
the Channel BW function on the TV mode functions menu.
To measure digital channels C/N ratio in Auto mode it is indispensable to tune channel
at its central frequency.
In the case of the presence of adjacent digital channels, these could mask the noise
level measurement when operating in Auto mode. Therefore, you are recommended to
use the Referenced mode.
In the case of an analogue terrestrial signal, when C/N (Auto) mode is selected, the
PROLINK-3/3C Premium
value will take several seconds to stabilize (six seconds at the most). An arrow below
the C/N readout represents the measurement cycle and it is necessary to wait the arrow
passes twice on the same point to guarantee a correct measurement.

4.9.1.4 Measuring the Power of Digital Channels (Channel power)

The PROLINK-3/3C
channels power, according to the active operation mode: Automatic method in TV
mode and Integration method in Spectrum mode. The Automatic method measures
digital channel power in the measurement filter bandwidth and estimates total channel
power assuming that spectral density is uniform throughout channel bandwidth. On the
other hand, the Integration method takes into account signal spectral distribution so
measurement is more accurate but slightly slower (see 4.10.2 Selecting the
Measurements Mode). The obtained measurements using these methods may differ
some dBs, specially when the digital signal is degraded.
06/2005
Premium
C/N (AUTO)
20.1 dB
VIDEO CARRIER:
FREQUENCY
= 1345.5 MHz
LEVEL
=
NOISE:
LEVEL
=
CHANNEL BW
=
performs an in-channel measurement, this involves that C/N
Premium offers two different methods to measure digital
64.1 dBuV
44.1 dBuV
32.0 MHz

IMPORTANT REMARK

IMPORTANT REMARK
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