I thought *** was going to handle this but the tech they sent out was gonna daisy chain 4 splitters in order to get me 8 signals. Ummm.....NO! FYI the service I have is digital and TV/Internet come in on one Coax cable.

I did all the multimedia wiring in the house. One outside line comes into the house. I have 7 locations for CATV and I also need to hook up one modem then get the modem to an ethernet router.

My question involves splitting the signal. One 8-way splitter would work physically, but I don't know what is going to happen to the signal. Do I need to put an amplifier in the mix? What happens to the internet leg of the splitter? Does it matter? What is the best way to do this?

Should I put the amplifier(what size) before the splitter? Should I get 2 1 into 4 signal amp/splitter combos?

Recommendations on hardware and where to get it would be nice as well.

 

I have a splitter feeding my modem directly then the 5 TVs come off the other side thru splitters. I dont have any signal quality problems.

My aunts house on the other hand, has 3 TVs and the cable modem is pulled off near one of the TVS. they get about 1/2 the bandwidth as myself (same neighborhood) and occationally one of their TVs loose channel 20.

 

Let's see, IIRC . . .

Every time you split the incoming signal, the resulting two outputs are 3db lower in strength than the original. This holds true for all multiples. This is ignoring any losses presented by the splitter itself (the better quality manufacturers will show the loss in db in the devices cut sheet).

Do you need a line-amp? You'd do best by finding out the actual signal level as it enters the house. 0db? +10db? +20db?

If you've a very strong feed level such as +20db, then you may very well not need a line-amp as there'd be enough for a grade A picture once it's split.

Another approach would be to get a distribution amp (pretty much a line amp and multiple splitter combo).

The stick in the mud would be to ensure all equipment is digital compatible.

As far as the Internet signal goes, it's running at a different frequency from the TV mess, but the design and application is similar.



FYI, it's possible to daisy-chain drop-taps to arrive at your goal. These look like regular splitters but are intended for large MATV & CATV systems like used in a hotel for example. They allow a strong, distribution level signal to be fed on one line around an entire floor. Each room would have a drop-tap that is selected by its Tap Attenuation. The first room might have an 18db attenuation value as the feed signal is very strong. Those further down the line might have 12db attenuation value, and so on.

NOTE: ALL unused ports/taps must be properly terminated by way of a 75ohm terminator (it just screws on).

Hope this helps.

Further reading . . . . http://www.atvresearch.com/atvwp5.html

 

my house was built new in '89 and prewired for catv in every room using the old crappy rg59 coax. it had 2 and 3 splitters stacked on top of each other. reception was always poor. about 2000, the cable signal went digital and reception got even worse. i cussed a lot but didn't know how to fix it. so a year or so ago the cable company finally offered internet service and a tech comes out and hooks up his tester and shakes his head alot and said, this is not going to work. my options were for him to run new wires into the house with a big honking drill, or i could rewire it myself. he gave me a spool of rg6 coax, a couple of splitters, and an amp (yes gave) and told me what to do...

he would bring 2 wires from the street to the house (bigger than rg6, not sure of the number). one for tv, one for network. i would pull 2 new RG6 wires from the entrance, through the garage, down to the center of the basement of the 2 story house.

the network wire would continue unspliced up to the living room and connect to the cable modem and wireless router.

from the center of the basement i pulled 5 wires for tv. one short wire up to the living room. 4 long wires up to the attic, and then down into the 4 bedrooms (no splices- home runs in catv lingo). at the center of the basement was my junction point. the tv input went first into the amp, and then a 4 way splitter. one output of the 4 way went into a 2 way splitter. this gave me 3 strong outputs (-7db) and 2 slightly weaker outputs (-11db). (this provided stronger signal on three tvs than if i had used the 8 way splitter).

WOW. what a difference. excellent tv picture and internet signal.

pulling the wires was a pain, but i was able to tape the new wires onto the old and pull them up through the walls of the house with little problem. only in the garage wall did it get too tight, i got in too big a hurry, pulled too hard and lost it. i was able to remove the paneling in the garage to put it back together.

so to answer the original question of the post.
1. what is the best way to do this.... see above.
2. Should I put the amplifier(what size) before the splitter? yes..15-20 db....but..
3. Should I get 2 1 into 4 signal amp/splitter combos? ask about whether you can put an amplifier on the ethernet link or not...

bc8747 is right, it all depends on how strong your signal is, as measured by the catv tech. +20, +15, +10 is good.

if you have to split one line, use a 2 way splitter first, taking one output to your cable modem. take the other output to an amp, and then the tv splitters.

more thoughts.
you will get a huge loss from a 8 way splitter, so you should amplify it first.

amplifiers come in 2 flavors, one way or 2 way. if you use ppv or other interactive services i think you need a 2 way. I don't know if you can amp the internet signal or not ? I didn't, instead using a dedicated wire all the way back to the entrance. my amp is +20db, 2 way. the cable guy gave it to me. its probably $50+.

don't split the line any more than absolutely necessary.
2 way is -3.5 db.
4 way is -7
8 way is -11 (thats a huge amount)...

2 4-ways is 3.5 + 7 = 10.5 (same as a 8 way).

 

Thanks for the GREAT replies guys.

I have heard from several people now that the Internet line should be split off of the main and not be amplified.

I have heard from an A/V installer that an amp before the 8 way should do the job.

What is new to me is the 2 way feature. I need to do some more research on that.

 

I would still measure the incoming signal after the Internet splitter. If you find a very strong signal (such as +20db), then skip the line-amp altogether as you'll end up with a +9db signal (+/-) at the 8-way splitters output(s). You'll also not have any Amp introduced harmonics or distortion, etc.

That's plenty strong for a grade A picture.

You don't want to risk overloading the A/V devices (load) input.

 

So ASSUMING that the incoming signal is where it needs to be from the cable company:

The main line when split with a 2-way will lose 3.5dB to each leg. Internet will receive one of those. The other will then hit an 8-way splitter which will lose 11dB. So if I amplify the signal going to the 8-way with a 15dB amp then it will be very close to the incoming signal strength at each leg.

3.5+11=14.5 dB loss

15dB gain will neutralize the loss at each TV leg of the 8-way splitter.


Then, if I measure the signal after the 8-way, what is the ideal number to have coming off of each leg of the split?

 

i can't answer what your minimum signal needs to be for good picture. i can say that i originally had some signals of -10 and -15 and the picture quality was crap.

just an example of bi-directional (2-way). (says its ok for cable modem...)
http://www.cablestogo.com/product_li...?cat%5Fid=2402

example of cheaper single direction amp. this one doesn't amp the higher frequencies.
http://www.audio-discounters.com/ph61107.html