Triplett CableRater- PN: 3279 - Manual (Page 22)

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A ‘star’ or ‘home run’ scheme is often used. A coaxial cable (coax) from each
room is run back to a common point, where the splitters and amplifiers are
located. This might be a Structured Wiring panel or a board attached to a base-
ment wall. In some localities, all of the coaxes exit the side of the house, to a
patch panel that can be serviced without requiring entrance to the house.
It is usually desirable to use a splitter with the minimum number of required
outputs. That is, if you have 3 TV’s, it is usually desirable to install a 3 way
splitter instead of, for example, an 8 way splitter. Because a 3 way splitter has
less loss than an 8 way splitter, using a 3 way splitter will provide a stronger
signal to each TV. An instance in which you may want to use a splitter with more
outputs than is necessary, is if your cable TV provider supplies a very strong
signal that causes your TV to overload. If this happens, installing a splitter with
more outputs will reduce the signal level on each output. Alternately, an in-line
attenuator can be used to reduce the signal level.
9.8.4 Is an amplifier needed?
If a large number of outlets are to be used, a large splitter, like a 16 way or more
may be needed. Use of a large splitter may reduce the signal level below the
minimum acceptable level at each outlet. For example, if the level provided by
the cable company is +10dBmV, and a 16 way splitter is used, with 16dB of Loss
on each output, then, neglecting any cable loss, the level at each TV outlet will be
-6dBmV (+10dBmV - 16dBmV = -6dBmV). If cable Loss is included, the level at
each outlet will probably be a few dB lower. A -6 to -8dBmV signal will probably
produce a poor quality (snowy) TV picture.
There are several solutions to this problem. The Cable TV Provider may be able
to increase the signal level delivered to the premises. Or, an amplifier can be
used to raise the +10dBmV signal level to a higher level before applying it to the
splitter. Figure 10 shows an example of an amplifier connected between the
Provider’s signal and the splitter.