76.605(a)(4)
Fact
The visual signal level, across a terminating impedance which
correctly matches the internal impedance of the cable system
as viewed from the subscriber terminal, shall not be less
than 1 millivolt across an internal impedance of 75 ohms
(0 dBmV). Additionally, as measured at the end of a 30
meter cable drop that is connected to the subscriber tap, it
shall not be less than 1.41 millivolts across an internal
impedance of 75 ohms (+3 dBmV). (At other impedance values,
the minimum visual signal level, as viewed from the
subscriber terminal, shall be the square root of 0.0133(z)
millivolts and, as measured at the end of a 30 meter cable
drop that is connected to the subscriber tap, shall be 2
times the square root of 0.00662(z) millivolts, where Z is
the appropriate impedance value).
Myth
"You can't have more than 3dBmV at the Subscribers terminal."
This one is not heard too often, but it does come up from time to time. I think that it is
this part of the regulations that cause the misconception over what should be at the Sub's
Terminal. While this part does not state what is too much, it does state what is too little.
76.605(a)(5)( i i i ) states what is too much.
Measurements
There are several types of meters on the market today to make these types of
measurements. 76.609(a)provides some suggestions on how to perform
other tests and 76.601(a)(1)provides test point and data collection information.