Promax PROMAX-4, Руководство пользователя

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USER’S MANUAL. PROMAX-4
Novembre 1999 Page 23
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Example 13. Measuring the C/N ratio for the following signal
Video carrier level = 82 dBµV (22 dBmV)
Real C/N ratio = 42 dB
C/N ratio measured = 42 dB ± error (see Appendix E)
Display shown after a 5-second wait.
Leave the C/N mode simply by pressing any key or turning the rotary switch.
Example 14. Measuring the C/N ratio of high-quality signals
Video carrier level = 113 dBµV (53 dBmV)
Real C/N ratio = 62 dB
C/N ratio measured >53 dB
The C/N measurement ranges and the accuracy of the measurement are
described in Appendix E.
Example 15. Measuring the C/N ratio of low level signals. (<70 dBµV)
The C/N ratio measurement dynamic is proportional to the video carrier level.
So, when the video carrier level is lower than 70 dBµV, the C/N measurement dynamic
does not surpass 40 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 dBµV
Real C/N ratio = 43 dB
C/N ratio measured >34 dB