76.605 a 8 i, ii
Coherent Disturbances
"The ratio of visual signal level to the rms amplitude of any coherent disturbances such as intermodulation
products, second and third order distortions or discrete-frequency interfering signals not operating on proper
offset assignments shall be as follows:
The ratio of visual signal levels to coherent disturbances shall not be less than 51 decibels for noncoherent channel
cable television systems, when measured with modulated carriers and time averaged; and
the ratio of visual signal level to coherent disturbances which are frequency-coincident with the visual carrier
shall not be less than 47 decibels for coherent channel cable systems, when measured with modulated carriers and
time averaged."