4.2.3.2 M easure of the V / A ratio (analogue channels)
This function allows the user to measure the ratio of the signal levels of the
video carrier of an analogue channel and the corresponding audio carrier of the
same channel. In addition, there is an automatic demodulation of the sound in FM
or AM, in accordance with the option selected, as explained in Point 4.2.5.1.
Follow the steps below to take this measurement:
1) Select the analogue channels measuring mode
2) Tune the desired video carrier and wait a few seconds until the read level
is stabilized.
3) Press the V /A [15] key
4) Wait until the measurement is stabilized (3 seconds maximum)
E xample 6
. Measuring the V/A ratio for the following signal
Video frequency
=
C55 (743.25 MHz)
Video carrier level
=
74 dBµ V (14 dBmV)
Audio subcarrier frequency = 5.5 MHz
Audio carrier level
=
64 dBµ V (4 dBmV)
Leave the V/A mode simply by pressing any key or turning the rotary switch.
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