~ The FCC and the Cable
Industry
The Federal Communications
Commission (FCC) is the U.S. govern-
ment agency responsible for regulat-
ing the cable industry and enforcing
technical standards regarding cable
system leakage. Protecting the public
against RFI related problems from
computers, power lines, industrial
equipment, and communication
devices (e.g. cordless telephones,
cordless microphones, and other low
power equipment) are also included
in the FCC’s responsibilities.
The FCC as specified in 47, Code of
Federal Regulations, parts 15 and 76
regulates cable television. According
to the FCC, a cable system is defined
as a “non-broadcast facility” because
its signal is transmitted over “closed”
cables. Cable signals theoretically
should not interfere with other signal
reception because cable signals are
enclosed and shielded. Unfortunately,
the closed cable system is subject to
cable breakage, product malfunction,
improper installation, and occasional
vandalism. If cable leakage is left
unmanaged, it can have a dramatic
effect on air traffic control, television
quality, data communications, and
telephone services.
5-1
Appendix A
5
~ Testing Beyond Regulation
In addition to the leakage require-
ments cited above, it becomes even
more necessary to test for leakage
when services such as telephony and
high-speed data are planned or imple-
mented, using the reverse path.
These services are susceptible to
interference from signals that may
ingress at a leak point. Because criti-
cal leaks are found at the drop and in
the house, it becomes necessary to
monitor for leaks at as low a level,
with as high a sensitivity as possible.
A leak that reads 19.5 µV/m in the
street may be significantly larger
inside the residence. The distance
compensation feature of Acterna’s CLI
products makes a best effort at cor-
recting for distances, but reflections,
phase summing and canceling can
have an effect on accuracy of these
readings. Therefore, government reg-
ulations require that measurements
should be conducted in the following
consistent manner: 10 feet / 3 meters
from the leak and 10 feet / 3 meters
off the ground. The best practice is to
find the biggest leaks first, then grad-
ually increase the sensitivity of the
leakage meter in order to find every
leak regardless of size. Then, of
course, “fix it.”
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