The house I'm living in has two cables that run from the outside wall
through the attic and into the living room and master bed room
respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic, attach a
four way cable splitter to it then run the wires (the fish tape aspect
doesn't seem like fun but there is plenty of space in the attic so it
seems doable) to the remaining bedrooms?

Is it possible to estimate the signal loss going this route? I plan
to run the 'in' from the outside wall to the 'in' on the splitter.
then all four 'outs' will get routed to the four bedrooms.

Thanks in advance

wrote...
The house I'm living in has two cables that run from the outside wall
through the attic and into the living room and master bed room
respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic, attach a
four way cable splitter to it then run the wires (the fish tape aspect
doesn't seem like fun but there is plenty of space in the attic so it
seems doable) to the remaining bedrooms?

Sure. That's what an installer might do. He might also do it outside the house,
adding splitters as needed, and drill through the outside wall at each bedroom.

Is it possible to estimate the signal loss going this route? I plan
to run the 'in' from the outside wall to the 'in' on the splitter.
then all four 'outs' will get routed to the four bedrooms.

IIRC, the last cable installer told me about -7dBmV per splitter. If you have
digital phone, that will suffer first, because it needs a cleaner signal. An
in-line amplifier BEFORE the splitter may boost the signal enough to keep it
clean if you need more.

The house I'm living in has two cables that run from the outside wall
through the attic and into the living room and master bed room
respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic, attach a
four way cable splitter to it then run the wires (the fish tape aspect
doesn't seem like fun but there is plenty of space in the attic so it
seems doable) to the remaining bedrooms?

Is it possible to estimate the signal loss going this route? I plan
to run the 'in' from the outside wall to the 'in' on the splitter.
then all four 'outs' will get routed to the four bedrooms.

OK, you made me get my manual.

The signal loss due to 75-ohm cable length will be 1.5-6.09 dB
(37%-75%) for every 100 feet of cable, depending on channel frequency.
4dB is a good rule of thumb. But in your case, the length will be the
same, you're just putting a splitter in the middle.

The splitter is the killer. A two-way splitter has about a 4dB loss on
each output (61%). For simplicity, assume the signal is cut in half. A
four-way splitter is electronically the same as a two-way with another
two-way on each output, so you get 8dB loss on each output, leaving you
with only one-fourth the signal that went in.

You also had a splitter outside the house that (two cables, remember)
that cut the signal in half. The signal that reaches your bedrooms will
be only 12.5% of the original signal, and even less because of the line
loss.

These signals are often too weak to work with digital equipment. I can
tell you from experience that your cable modem needs a full-strength
signal.

Get a high-quality signal amplifier and install it before *any* of the
splitters. Keep your runs as short as possible.

--
Steve Bell
New Life Home Improvement
Arlington, TX USA

"SteveBell" wrote in
:


OK, you made me get my manual.

The signal loss due to 75-ohm cable length will be 1.5-
6.09 dB
(37%-75%) for every 100 feet of cable, depending on
channel
frequency. 4dB is a good rule of thumb. But in your case,
the
length will be the same, you're just putting a splitter in
the
middle.

The splitter is the killer. A two-way splitter has about a
4dB
loss on each output (61%). For simplicity, assume the
signal is
cut in half. A four-way splitter is electronically the
same as a
two-way with another two-way on each output, so you get
8dB loss
on each output, leaving you with only one-fourth the
signal that
went in.

You also had a splitter outside the house that (two
cables,
remember) that cut the signal in half. The signal that
reaches
your bedrooms will be only 12.5% of the original signal,
and
even less because of the line loss.

These signals are often too weak to work with digital
equipment.
I can tell you from experience that your cable modem needs
a
full-strength signal.

Get a high-quality signal amplifier and install it before
*any*
of the splitters. Keep your runs as short as possible.


In other words, if possible, lose the splitter outside the
house and have only one line to the attic. Put a GOOD amp in
the attic on the one remaining line. Then wire in a four-
way splitter right next to it. Look around and find the
best splitter you can. There is a big difference in
internal losses between the cheap ones and the top-of-the-
line. Forget Radion Shack - find a reputable cable/home
entertainment installer and buy from them. If you can't
find one, go to www.grainger.com and pick out the best
there. Now, to make up for the feed you lost, find the two
shortest runs of the five you want. Feed them from one of
the outputs of the four-way splitter. That way the three
longest runs, or the three drops that have phones/cable
modems/etc. will get the most signal.

Also, make sure you get the F-connectors that solder on.
Any of the connectors that screw/crimp on and use the center
conductor of the RG-6 cable as the center contact will have
more loss and a higher likeleyhood of failure. And make
sure you are using RG-6, not RG-59 or anything else. The
few extra dollars spent here will be more than worth it.

I know this is confusing if you haven't worked with it, but
here is a nice little tutorial that should answer most of
your questions. Ignore any of the parts about combiners and
modulators, since you are not doing any of that.

http://www.hometech.com/learn/video1.html

If you have any other questions feel free to drop me a line
directly.

In article , "JR Weiss" wrote:
wrote...
The house I'm living in has two cables that run from the outside wall
through the attic and into the living room and master bed room
respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic, attach a
four way cable splitter to it then run the wires (the fish tape aspect
doesn't seem like fun but there is plenty of space in the attic so it
seems doable) to the remaining bedrooms?

Sure. That's what an installer might do. He might also do it outside the
house,
adding splitters as needed, and drill through the outside wall at each bedroom.

Is it possible to estimate the signal loss going this route? I plan
to run the 'in' from the outside wall to the 'in' on the splitter.
then all four 'outs' will get routed to the four bedrooms.

IIRC, the last cable installer told me about -7dBmV per splitter. If you have
digital phone, that will suffer first, because it needs a cleaner signal. An
in-line amplifier BEFORE the splitter may boost the signal enough to keep it
clean if you need more.

An amplifier in front of a modem has to be two way. I had one in the old house, but the cable guy
took it off. Seems like it may have caused a proble,

greg

In article , "JR Weiss"
wrote:
wrote...
The house I'm living in has two cables that run from the outside
wall through the attic and into the living room and master bed
room respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic,
attach a four way cable splitter to it then run the wires (the
fish tape aspect doesn't seem like fun but there is plenty of
space in the attic so it seems doable) to the remaining bedrooms?

Sure. That's what an installer might do. He might also do it
outside the house,
adding splitters as needed, and drill through the outside wall at
each bedroom.

Is it possible to estimate the signal loss going this route? I
plan to run the 'in' from the outside wall to the 'in' on the
splitter. then all four 'outs' will get routed to the four
bedrooms.

IIRC, the last cable installer told me about -7dBmV per splitter.
If you have digital phone, that will suffer first, because it needs
a cleaner signal. An in-line amplifier BEFORE the splitter may
boost the signal enough to keep it clean if you need more.

An amplifier in front of a modem has to be two way. I had one in the
old house, but the cable guy took it off. Seems like it may have
caused a proble,

Amplifiers increase the noise as much as the signal, or more if it's a
cheap amplifier. Cable modems and other digital devices need to be
connected to the strongest signal available.

--
Steve Bell
New Life Home Improvement
Arlington, TX USA

"GregS" wrotete:

IIRC, the last cable installer told me about -7dBmV per splitter. If you have
digital phone, that will suffer first, because it needs a cleaner signal. An
in-line amplifier BEFORE the splitter may boost the signal enough to keep it
clean if you need more.

An amplifier in front of a modem has to be two way. I had one in the old
house, but the cable guy
took it off. Seems like it may have caused a proble,

When Comcast re-installed my service to accommodate phone service, they put a
new amp at the drop because of a low signal. A couple weeks later they repaired
a bad splice at the pole, and the signal went WAY up. Amp is still there,
though, and has caused no problems.

On Tue, 20 Jan 2009 15:45:39 +0000 (UTC), "SteveBell"
wrote:


In article , "JR Weiss"
wrote:
wrote...
The house I'm living in has two cables that run from the outside
wall through the attic and into the living room and master bed
room respectively.

I'd like to add cable to three other bedrooms in the house. The
question: Can I splice one of the cables within the attic,
attach a four way cable splitter to it then run the wires (the
fish tape aspect doesn't seem like fun but there is plenty of
space in the attic so it seems doable) to the remaining bedrooms?

Sure. That's what an installer might do. He might also do it
outside the house,
adding splitters as needed, and drill through the outside wall at
each bedroom.

Is it possible to estimate the signal loss going this route? I
plan to run the 'in' from the outside wall to the 'in' on the
splitter. then all four 'outs' will get routed to the four
bedrooms.

IIRC, the last cable installer told me about -7dBmV per splitter.
If you have digital phone, that will suffer first, because it needs
a cleaner signal. An in-line amplifier BEFORE the splitter may
boost the signal enough to keep it clean if you need more.

An amplifier in front of a modem has to be two way. I had one in the
old house, but the cable guy took it off. Seems like it may have
caused a proble,

Amplifiers increase the noise as much as the signal, or more if it's a
cheap amplifier. Cable modems and other digital devices need to be
connected to the strongest signal available.

Right. Amplifiers are only good for making up for losses *after* the
amplifier.

Lots of valuable info here. I'll make an attempt at getting this done
this weekend. Thanks alot

tim wrote:
"SteveBell" wrote in
:

OK, you made me get my manual.

The signal loss due to 75-ohm cable length will be 1.5-
6.09 dB
(37%-75%) for every 100 feet of cable, depending on
channel
frequency. 4dB is a good rule of thumb. But in your case,
the
length will be the same, you're just putting a splitter in
the
middle.

The splitter is the killer. A two-way splitter has about a
4dB
loss on each output (61%). For simplicity, assume the
signal is
cut in half. A four-way splitter is electronically the
same as a
two-way with another two-way on each output, so you get
8dB loss
on each output, leaving you with only one-fourth the
signal that
went in.

You also had a splitter outside the house that (two
cables,
remember) that cut the signal in half. The signal that
reaches
your bedrooms will be only 12.5% of the original signal,
and
even less because of the line loss.

These signals are often too weak to work with digital
equipment.
I can tell you from experience that your cable modem needs
a
full-strength signal.

Get a high-quality signal amplifier and install it before
*any*
of the splitters. Keep your runs as short as possible.


In other words, if possible, lose the splitter outside the
house and have only one line to the attic. Put a GOOD amp in
the attic on the one remaining line. Then wire in a four-
way splitter right next to it. Look around and find the
best splitter you can. There is a big difference in
internal losses between the cheap ones and the top-of-the-
line. Forget Radion Shack - find a reputable cable/home
entertainment installer and buy from them. If you can't
find one, go to www.grainger.com and pick out the best
there. Now, to make up for the feed you lost, find the two
shortest runs of the five you want. Feed them from one of
the outputs of the four-way splitter. That way the three
longest runs, or the three drops that have phones/cable
modems/etc. will get the most signal.

Also, make sure you get the F-connectors that solder on.
Any of the connectors that screw/crimp on and use the center
conductor of the RG-6 cable as the center contact will have
more loss and a higher likeleyhood of failure. And make
sure you are using RG-6, not RG-59 or anything else. The
few extra dollars spent here will be more than worth it.

Amp goes as close to antenna as possible- even with high-quality cable,
you will be amplifying noise as well as signal, if it is 50 feet away in
the attic. In 40-some years of amateur cabling, I have never seen a
solder-type Type F connector that goes on a cable end, much less one
with a built-in pin. (not saying they don;t exist, but I have never seen
one.) Your description sounds like the PL-259s we used to use in CB,
back in stone age. Amphenol was the standard. We make Mil-Spec RG6q
cables at work for 2-way satt systems. We use compression connectors, a
higher quality version of what you can find at the Borg. ($200 tool, $5
connectors) They use the center conductor as the pin on the connection,
but the thickness and quality of the conductor are better than retail
cable. The plastic ring, pressed backwards into the connector from the
cable end, holds and waterproofs as well as any soldered connection.
--
aem sends...