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Signal-to-Noise Ratio Measurements (TV)
The Combolook Color
HD
is capable of performing measurements of the Signal/Noise or
Picture-Carrier/Audio-Carrier ratio.
To perform these measurements:
•
Put the marker on any signal carrier and ”zoom in” with the ”Span 13
Span 13
Span 13
Span 13 ” button.
•
Push Ref mrkr
Ref mrkr
Ref mrkr
Ref mrkr, for the reference marker setting.
•
Tune in the ”right” frequency with the marker so that it is a the peak of the signal
to measure.
•
Push Ref set
Ref set
Ref set
Ref set and a new marker appears on top of the first marker.
•
Turn the knob and place the reference marker on another carrier (signal peak), or
on the
noise-floor
.
•
The relation between the first marker and the second marker is presented in the
lower right hand corner of the picture-screen so in the spectrum below we see
that the audio carrier is 7dBuV lower that the picture carrier and the video/audio
carrier spacing is 5.5MHz.
This measurement can also be made from Spectrum samples saved in memory. After a
spectrum is loaded from memory with “Memory -> Load” choose” Ref mrkr” and use the
knob and set the first marker position with “Ref set” and then use the knob to define the
second reference marker.