Promax PROLINK-4 Manual De Instrucciones página 201

USER'S MANUAL. PROLINK-4
4.10.2.3 Measuring the Power of Digital Channels (Channel Power)
In the Spectrum Analyser mode the PROLINK-4 measures digital channel
power using an Integration method between channel limits which are defined by the
user. To show the interest of this method, imagine a spectral distribution like the one
shown in the following figure (channel bandwidth is 8 MHz defined by the markers). If
channel power is measured in TV operation mode different readouts will be obtained
depending on the tuned frequency (measurement filter bandwidth is 230 kHz), if tuning
is shifted from 759 MHz to 762 MHz reading will increase in several dB.
Figure 43.- Channel power measurement in Spectrum Mode.
When measuring Channel power, on the lower part of the image appears the
tuned frequency (or channel), the channel bandwidth (Channel BW) and the Channel
Power.
To measure the channel power, first of all it is necessary to define channel
bandwidth, that is to say to set the limits of the integration: select the Channel
bandwidth function in the functions menu and then, again in the Spectrum mode, turn
the rotary selector to modify it or well press key
will be erased and using the keyboard introduce the new value. Finally accede to the
functions menu again and execute the Marker function in order you can tune new
carrier frequencies, then when turning the rotary selector, the tuning marker and the
channel bandwidth limits will shift together.
To measure digital channels power correctly it is indispensable to tune channel at its
central frequency and to define channel bandwidth.
02/2003
[31], current channel bandwidth
IMPORTANT REMARK
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