USER’S MANUAL. PROMAX-10
Premium
Page 36
05/2004
This measurement is used to be carried out on the return path and permits to
detect intermittent interferences.
Since on this operation mode the PROMAX-10
Premium
holds on the screen
the maximum measured value (through a dotted line), after making several
measurements over the band, it will be possible to detect impulsive type interferences. It
is advised to previously define a reference line which actuates as a maximum noise
threshold (30 dBµV on previous figure).
4.2.4.3
MIN operating mode.
This measurement permits to detect permanent channel interferences that in an
other way could remain masked because of the variable nature of the signal. It is
interesting in analogue channel measurements as well as in digital channel.
To select this representation mode you must select the MIN mode, MINIMUM
INGRESS (see section 4.2.4.5. Spectrum mode configuration menu).
In this operating mode it is advised to select the Average detector (see section
4.2.4.5. Spectrum mode configuration menu).
Figure 33.- MIN mode. First scan.
Figure 34.- After several scans.
Previous figures show an example of this measurement over a digital channel.
Left figure corresponds to the first sweep. After several sweeps (right figure) an
interference is seen at the centre of the channel, which previously remain masked by
the noisy nature of the signal.
4.2.4.4
TRANSIENT DETECTOR operating mode
IMPORTANT
The Transient detector mode is only operative in the return path.
The TRANSIENT DETECTOR mode allows to count the number of transitory
with a level higher than a certain threshold. The threshold is defined by the user
(between 20 and 60 dBµV) as well as the detection frequency range.
The SCAN field shows the margin of
frequencies on which the detector acts (the higher
frequency can be reduced by means of the STOP.
FREQ. parameter on the configuration menu).
The lower line (TIME) shows the time since
the detector is active.
Figure 35.- Transient detector mode.
