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StarServe Installers Guide

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page 41

Approximating Signal Level

The tuner in modern televisions have a ‘knee’ in performance at

about -10dBmV input signal strength. Below this ‘knee’, the noise

begins to increase rapidly. (Note: Noise is identifiable as snow.

If there is a pattern to when it is seen, it is not noise).

1. Connect the variable attenuator to the TV set and tune to

a station.

2. Increase attenuation until the ‘knee’ is found (the point

where noise begins to rapidly increase). Noise is easiest

to see on a black background, wait until the screen turns

dark to perform this test.

3. Note the amount of attenuation add this number to -10dBmV.

4. This is the signal strength of this station.

5. Typical accuracy of this method is about +/- 3dB.

This technique can also be used to identify stations that are

far stronger than the other stations (these can cause problems

when using an RF amplifier).

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Clipsal STARSERVE Specifiche Pagina 40