E xample 8.
Measuring the C/N ratio of high-quality signals
Video carrier level
=
113 dBµ V (53 dBmV)
Real C/N ratio
=
62 dB
C/N ratio measured
>
50 dB
The C/N measurement ranges and the accuracy of the measurement are
described in Appendix E.
E xample 9.
Measuring the C/N ratio of low level signals. (<70 dBµ V)
The C/N ratio measurement dynamic is proportional to the video carrier level.
So, when the video carrier level is lower than 70 dBµ V, the C/N measurement
dynamic does not surpass 50 dB (see Appendix E). If the C/N ratio to be measured
is higher than this value, the instrument will indicate it by means of the symbol >.
Video carrier level
=
65 dBµ V
Real C/N ratio
=
48 dB
C/N ratio measured
>
44 dB
