Promax US TV EXPLORER II Manual De Uso página 60

As well as the video carrier / noise level ratio (C/N) (40.1 dB in previous figure),
the frequency or channel (depending on the tuning mode selected) and the level of the
video carrier and video/audio ratio are also shown. When representing the spectrum by
means of pressing
of the carrier tuned. That is, the cursor will indicate the point where the value of the
noise is lower, whenever the C/N(AUTO) option is selected from the PREFERENCES
[22] menu. If the C/N (MANUAL) option has been activated the frequency where
noise level will be measured will correspond to the position of the vertical discontinuous
green-colored cursor that appears in the spectrum graph
In order to modify this frequency, press the measurement configuration
[17] key, to access the CONFIGURATION menu. By turning the rotary selector
[1], locate the NOISE cursor on the position of the marker using
option (see section "5.16.1 Markers") or directly enter the value of the new
MARKER
noise frequency by means of
70
60
50
40
30
CH:
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 option on the Measurements Configuration menu that appears
when pressing [17] key.
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.
Page 52
[13] key, the NOISE cursor is automatically positioned to a side
option.
NOISE FREQ
FREQ:
C/N REF:
43
Figure 29.- NOISE cursor. C/N (MANUAL).
USER'S MANUAL. US TV EXPLORER
[13].
650.00 MHz
16.5 dB
SPAN: 32 MHz
IMPORTANT REMARK
II
NOISE FREQ. TO
11/2013