[Discuss] Extra splitter (OT)

[cra at WPI.EDU (Chuck Anderson)]

On Sun, Sep 04, 2011 at 05:53:30PM -0400, edwardp at linuxmail.org wrote:
> The recent thread regarding RCN, reminded me of the AT&T BB installation  
> 10 years ago.  They installed an additional splitter (two-way) with one  
> cable going into the cable modem and the other cable going into another  
> splitter (three-way) going to the TV's.  At the time of the  
> installation, they also installed a filter on the other cable going from  
> the two-way to the other splitter, but eventually Comcast removed it as  
> it was no longer required.
>
> With the technological advances made since then, is this extra two-way  
> splitter still required today, or could everything now go into one 
> splitter?

You can use a three-way splitter.  Those are usually marked with a
"high" output with lower dB loss--connect that one to the cable modem.
For each two-way splitter, you lose a bit more than half the signal
(3.5 dB up to 1 GHz for good splitters, worse for cheap ones).  Any
bigger splitters are internally just networks of two-way splitters,
and the same thing holds true.  E.g. a three-way splitter looks like
this inside:

     __-3.5dB__Out
In--|             __-7dB__Out
     ~~-3.5dB~~~~|__-7dB__Out

So the first output's power is less than half the input power, and the
other two are less than 1/4 the input power.

Just make sure you get a "good" splitter, 5 MHz - 1 GHz, 3.5 dB, $1-$3.
You don't need to spend extra for the "Monster" one though.