Power And C/N Ratio Measurement Of Digital Channels (Dvb-C / Dvb-T / Dab) (Only For Digital Channels) - Promax -8 SE Manual

USER'S MANUAL. PROMAX-8
MEASURING METHOD
When pressing
selector [9] again, we will accede to
the CSO-CTB distortion
measuring screen. First of all it will
appear the message PRESS TO MEASURE.
REMOVE CARRIER. That is to say, once the video
carrier level on which it is desired to make the
measurement appears on the screen, you must
press the rotary selector [9] in order that the unit
retains the carrier level and comes to calculate the CSO and CTB ratios; next you must
turn off the video carrier of the channel you want to make the measurement (at the right
of the CTB measurement will appear the message Carrier OFF).
The display will show the level of the video carrier (80 dBμV in the previous
figure) and the CSO ratio (accompanied by the frequency offset for which the minimum
ratio has been obtained) and the CTB ratio (with the message Carrier OFF or Carrier
ON according to the equipment has detected the absence or not of carrier).
The lower part of the screen shows the 4 measures made for the estimation of
the CSO value.
If the rotary selector [9] is pressed again, the unit will return to the measurement
screen of the video carrier + V/A + C/N (paragraph 4.2.3.1.1).
4.2.3.1.4 Power and C/N ratio measurement of digital channels
(DVB-C / DVB-T / DAB) (only for digital channels).
When the tuned channel has been defined as
digital by means of the Edit Channel Plan function
(see section 4.2.1 Global Configuration Menu) a
screen as shown in the attached figure will appear.
This screen shows the digital CHANNEL POWER (40
dBμV in the example) together with its related channel
bandwidth (BW = 8.0 MHz) and the Carrier/Noise
ratio (C/N=17 dB). At the bottom of the screen, as
in the case of analogue channels, a bar-graph represents the channel power, with a
resolution of 1 dB.
In order to measure digital channels correctly, previously, the channel must be
defined as digital (see Edit Channel Plan function at section '4.2.1 Global
Configuration) and, if necessary, the CHANNEL BW parameter should be
redefined by means of the configuration menu.
When a channel has been defined as digital, the
central frequency.
09/2013
SE
the rotary
products
Figure 17.- CSO and CTB
measurement.
C02 50.50MHz
CHANNEL POWER
BW=7.0MHz C/N=
INTEGRATING ...
60
20 40 80 100 120
Figure 18.- Measuring a digital
channel.
VERY IMPORTANT
PROMAX-8
SE tunes it at its
CCIR
70dBuV
28dB
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