Televes FSM 500, Руководство пользователя

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Figure 60.- V/A measurement. Frequency tuning
The tuned frequency is taken as the video carrier, in other words, it is where the video level is
measured. The audio carrier level is taken to be as many MHz higher as indicated in the Audio
information that appears onscreen (5.50 in the example). By pressing the
Freq. button, the
information on the tuned frequency is highlighted. Once this has been done, we can vary the
tuning by using the rotating knob or the number pad.
If we press the Chan. button, the information on the tuned channel will appear. The frequency
that is used to carry out the video level measurement will be the video carrier of the channel
that the equipment searches for automatically.
Therefore, when the equipment is in frequency tuning mode, it is the user’s responsibility to
make sure that the tuned frequency is really the video carrier of the channel that the V/A
measurement is to be carried out on, in order for the measurement to be totally correct.
If the level bar is visible when the V/A measurement is being carried out (see section 3.3.3.1.1.-
Bar ), two overlapping bars will appear, one in green which indicates the video carrier level
(channel tuning) or the tuned frequency level (frequency tuning), and the other in red which
indicates the audio carrier level.
Figure 61.- Indication of V/A using the bars
3.3.3.2.1.3.- Automatic C/N
When this function is selected, a window with the carrier / noise ratio will appear automatically
onscreen. The window that appears is the following:
3.3.3.2.1.1
3.3.3.2.1.2
3.3.3.2.1.3
3.3.3.2.1.4
Tuned
frequency
Signal level in the tuned
frequency
V/A measurement
Audio carrier
Audio carrier level
Multimetter FSM 500 Ref. 5903
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