Analogue Tv: Measuring The Video / Audio Ratio (V/A); Analogue/Digital Tv: Measuring The Carrier / Noise Ratio (C/N) - Promax PRODIG-3 Manual Del Usaurio

USER'S MANUAL. PRODIG-3
So, if there are ten carriers with a level around 90 dBµV, their equivalent level will be:
90 dBµV + 10 log 10 = 100 dBµV
Observe that in this case, loss of tuning by overload of the RF input may occur besides
other effects such as tuner saturation and generation of intermodulation products that
may mask the spectrum visualization.

5.14.2 Analogue TV: Measuring the Video / Audio ratio (V/A)

In the Audio/Video measurement mode, on the screen appears the following
information:
Figure 20.- Measurement of the video/audio rate
In addition to the video carrier / audio carrier level ratio (16.2 dB in previous
figure) it also shows the frequency or channel, depending on the tuning mode selected,
and the Carrier/Noise ratio.

5.14.3 Analogue/Digital TV: Measuring the Carrier / Noise ratio (C/N).

The PRODIG-3 carries out C/N ratio measurement in four different ways,
according to the carrier type and the used band:
A) Terrestrial band, analogue carrier
Carrier level is measured using a quasi-peak detector (230 kHz BW). Noise level
is measured with an average detector and corrected to refer it to channel
equivalent noise bandwidth (according to the definition of the selected standard).
03/2008
0 10 20
168.25 MHz
FREQ: LEVEL:
S10
CH: C/N:
» V/A:
30 40
79.2 dBµV
40.1 dB
16.2 dB
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