Taking Measurements; Measuring The Level Of Analogue Signals; Very Important - Promax MC-577 Manuel D'utilisation

USER'S MANUAL MC-577.

4.2.6 Taking measurements

The MC-577 enables three different kinds of measurements to be taken:
Analogue signals level measurement
Digital channels power measurement
C/N ratio measurement of analogue and digital signals.
The following sections describe how to take each one of these measurements.

4.2.6.1 Measuring the level of analogue signals

To measure the level of an analogue signal, proceed as described below:
- Select the Spectrum Analyser operating mode, SPAN mode, and with the help
of the frequency counter display [23] tune the signal using the TUNING [25] and
FINE TUNING controls [27]. Adjust the SPAN control [24] to select a bandwidth
so that the signal occupies the most part of the image. If you are dealing with a
television signal it is also possible to take the measurement from the Monitor
mode (in this case release the audio control [28] so that the measurement bar
appears at the top of the image).
- Select the measurement scale for analogue signals LEVEL [34], in order to do
this the DIG key [11] should be released and the ANALOG indicator [32] should
remain lit.
- Read the level on the screen with the help of the scale calibrated in dBµV (20-
80 dBµV) LEVEL [34]. If the level is very close to 80 dBµV or is greater than this
value, the signal should be attenuated using the RF attenuators.
On terrestrial bands the [16] 10 dB, [15] 20 dB and [14] 20 dB attenuation
keys must be pressed in order to obtain the signal level into the scale. The
total attenuation is the addition of the keys pressed.
- The actual signal level is calculated in the following manner:
Level [dBµV] = Measurement [dBµV] + Attenuation [dB] + Correction Factor [dB]
THE CORRECTION FACTOR IS OBTAINED FROM THE CORRECTION CHART
WHICH IS DELIVERED WITH THE INSTRUMENT. THIS VALUE DEPENDS ON THE
FREQUENCY.
05/2003

VERY IMPORTANT

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