cable tv amplifiers or layout

[TeleFragger]

my house came with a splitter outside... 1 in and 4 out.
only 4 bedrooms had cable

since then I added cable to the basement, garage, kitchen so that wasnt cutting it...
I did not understand cable tv db ratings and how they work... sp basj away...
I thought the splitter meant that it takes the signal down to that db level and didnt know that you loose that amount EACH time!!!!

thus my delema...

I only have 1 tv with digital cable... so my numbers..
I read that typically a house gets 9db coming in. This went to a 4 way splitter for a loss of 7db per leg or 2db at each leg. All great for the beginning..


I put a 2 way splitter in and ran 1 leg to feed that splitter and removed the living room wire from the 4 way and attached it to the 2 way. Cut that wire and ran it to the utility room. then patched it to the other locations. SInce I didnt know how dbs worked..... I pretty much had a mess....

-1.5db for my digital cable line so when it rained or snowed (like now) tv was choppy and horrible....

well I had a few 4 ways tied in downstream causing this issue... I still am not in a great position..

first 2 way for 3.5db loss goes to second one in util room for a total of 7db loss or going from -1.5 to 2db so now tv is alot better...... however I still had to plug everything else in including my cable modem..... so put the 4 ways back in and my cable modem is down to 0db... internet is still great and fast but I am trying to figure out if I need an amplifier....


so my questions now...

1. do I need an amplifier
2. what one do I want
3. where do I want to put it

bad part is that I could just put a big splitter in but they say the bigger the more loss per leg.... well seem the smaller the better than......

 

[lorenkoeman]

OK, it sounds like you have gotten a bit of an education on splitter losses so that is good.

I am not completely following what you setup is however, So a few questions:

How many outlets do you need active? I see that you have them in all 4 bedrooms, do you want those all hooked up? I generally leave them unhooked if I will not be using them in the forseeable future. Just adds to signal loss and potential for interference.

Are all these runs "home run" meaning all coming together in one place where your cable comes into the house? or do multiple outlets attach to one run to the first splitter?

It sounds like you may need an amp, but perhaps not if we can balance the signal strength to all the outlets and disconnect any that will not be needed in the forseeable future.

Can you upload a sketch of what you are trying to do? I think this would help a lot.

 

[TeleFragger]

well homeruns are for 3 bedrooms in use.... and all where the cable comes together..

then I ran the 4th bedroom as a homerun to the utility room to which there are approximately 4 there. so I need a total of 8 active.....

 

[Jiguana]

Generally the house will have 3-6 dBmv of analog RF signal at the ground block. There are some factors that can make this number fluctuate.
Anyway, the point is that with a digital STB and cablemodem and 6(?) other devices (TVs?) you will most likely need a amp.
Analog TV's can take a decent hit of RF loss (depending on make/model) compared to the analog or even the digital STB.

The best way for us to help is to get an idea of the distance between the splitter(s) to your end devices.
The cablemodem should be before any amp.
If you tell me the make of your digital STB I can probably help you tell how much RF level you have at the ground block.
What kind of coax is used? RG-59 or RG-6?
Did you use screw-on f-connecters or crimp?

Rule of thumb on splitter loss is 3.5dB of loss for every two ports.
2-way is 3.5, 4-way is 7dB, 8-way is 11/12dB.
The odd number ported splitters are different creatures. There are two flavors of 3-way splitters. The balanced and unbalanced.
The unbalanced will have two ports with a loss of 7dB and one with a loss of 3.5 dB.
The balanced (made by Regal) will have a loss of 5.5dB per port.

 

[Neurorad]

Don't forget you'll need a 110V AC outlet near the amplifier.

Still a little unclear on the location of the splits.

1 4-way where the cable enters the house...

Which run has the cable modem?

I bet you can get away with 1 amp at the split in the utility room, but a clearer description would be useful.