Digital Tv: Measuring The Power Of Digital Channels - Promax TV EXPLORER II User Manual

In order to measure digital channel C/N ratio 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.

5.14.6 Digital TV: Measuring the Power of Digital Channels

The TV EXPLORER II / II+ measures digital channel power in the measurement
filter bandwidth and estimates total channel power assuming that spectral density is
uniform throughout channel bandwidth.
On selecting the CHANNEL POWER measurement mode, the screen displays the
following information:
10
FREQ:
CH:
MPEG-2 TS
In addition to the power of the digital channel (55.8 dBµV in previous figure) this
also shows the tuning frequency or channel, depending on the tuning mode selected,
and the offset frequency to calculate the digital channel power and the deviation
frequency of the central tuning calculated by the demodulator, measurement that
indicates the adjustment in the channel tuning.
For the power measurement of a digital channel to be correct it is essential to have
previously defined the channel bandwidth using the Channel BW option, in the
Measurements Configuration menu that appears when pressing
Page 54
30 50 70
650.00 MHz
-3 kHz
43
Figure 28.- Digital channel power measurement.
USER'S MANUAL. TV EXPLORER II/II+
IMPORTANT REMARK
90 110
C/N: >21.3 dB
» POWER: 55.8 dBµV
MER: 19.5 dB
CBER: 5.0E-2
5.3E-4
VBER:
130
[17] key.
09/2009