(5) The visual signal level on each channel, as measured at the end of a 30 meter cable drop that is connected to the subscriber tap, shall not vary more than 8 decibels within any six-month interval which must include four tests performed in six-hour increments during a 24-hour period in July or August and during a 24-hour period in January or February, and shall be maintained within:
(i) 3 decibels (dB) of the visual signal level of any visual carrier within a 6 MHz nominal frequency separation.