Does Comcast filter by number of TVs?

olds

Elite Member
Mar 3, 2000
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A month ago, we had Comcast set up the cablebox for the HDTV and set up the internet modem.
Today I decided to hook up a tv in the bedroom with the cable that is in that room. After replacing the RG59 with RG6, it worked fine.
But when I went to get online, I had no signal at my modem. When I disconnected the TV and reset the modem, I had internet again.
Do they want you to pay per TV?
Diagram

Edited diagram for modem
 

boomerang

Lifer
Jun 19, 2000
18,883
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It quite sure it's a signal loss issue related to the splitters. I posted a link in the thread below with some good information in that regard.

http://forums.anandtech.com/me...id=38&threadid=2234421

I would be doing you a disservice telling you what you need to do to fix it as I have no practical experience dealing with amps and splitters. Hopefully the diagrams and information at that link will help. There is some good discussion in that thread too.

Edit: To answer your other question, in my area, I can receive approximately 22 channels without a decoder box from Comcast. Those signals can be received on as many TV's as I have / want. To get what they term digital channels, I must have a decoder box. One per TV. The rules spelled out in my link (to my link :D) apply. Each splitter and foot of cable results in a signal loss. Eventually the signal will be too weak to view.

You could have a bad splitter. Could there be more splitters hidden from view? In walls?
 

olds

Elite Member
Mar 3, 2000
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Could there be more splitters hidden from view? In walls?
I don't believe so, I can see all the runs from under the house.
And thanks for the link
 

boomerang

Lifer
Jun 19, 2000
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641
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http://pics.bbzzdd.com/users/boomerang/cable.jpg

This is how I would rewire it. You could still have too much signal loss at the bedroom TV, but your modem and HDTV should be fine. The only way to know about the bedroom is to try.

The circles are splitters.

Edit: The diagrams at the link I referenced show the cable modem being at the first splitter. This is consistent with everything I've ever read. So, I went ahead and made the diagram. As I said, I'm confident the Modem and HDTV will work fine. It's essentially what you had before. Putting the bedroom TV into the mix is what caused the problem. Putting the Modem too far downstream weakened the signal too much with the addition of the bedroom TV.
 

olds

Elite Member
Mar 3, 2000
50,122
778
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Originally posted by: boomerang
http://pics.bbzzdd.com/users/boomerang/cable.jpg

This is how I would rewire it. You could still have too much signal loss at the bedroom TV, but your modem and HDTV should be fine. The only way to know about the bedroom is to try.

The circles are splitters.

Edit: The diagrams at the link I referenced show the cable modem being at the first splitter. This is consistent with everything I've ever read. So, I went ahead and made the diagram. As I said, I'm confident the Modem and HDTV will work fine. It's essentially what you had before. Putting the bedroom TV into the mix is what caused the problem. Putting the Modem too far downstream weakened the signal too much with the addition of the bedroom TV.
What do you think of this?
Red

 

boomerang

Lifer
Jun 19, 2000
18,883
641
126
Originally posted by: oldsmoboat
Originally posted by: boomerang
http://pics.bbzzdd.com/users/boomerang/cable.jpg

This is how I would rewire it. You could still have too much signal loss at the bedroom TV, but your modem and HDTV should be fine. The only way to know about the bedroom is to try.

The circles are splitters.

Edit: The diagrams at the link I referenced show the cable modem being at the first splitter. This is consistent with everything I've ever read. So, I went ahead and made the diagram. As I said, I'm confident the Modem and HDTV will work fine. It's essentially what you had before. Putting the bedroom TV into the mix is what caused the problem. Putting the Modem too far downstream weakened the signal too much with the addition of the bedroom TV.
What do you think of this?
Red

Yeah, that should work. Weatherproof box I assume?

 

alfa147x

Lifer
Jul 14, 2005
29,307
106
106
I saw these splitter type looking things but they where called taps

How is this any different then a splitter?
sorry for this semi thread jacking oldsmoboat
 
Mar 10, 2005
14,647
2
0
Originally posted by: oldsmoboat

What do you think of this?
Red

:thumbsup:

Originally posted by: alfa147x
I saw these splitter type looking things but they where called taps

How is this any different then a splitter?
sorry for this semi thread jacking oldsmoboat

a tap is used to distribute signal from cable plant to subscribers' premises, with 2, 4 or 8 connections. if it was small and had F (regular cable) connectors, it was either a trap or filter (blocking frequency x to frequency y) or a directional coupler. a dc is like a splitter, but has 2 outputs of unequal signal loss, i.e. dc-8 has an output of -1 dB and an output of -8 dB. a 2-way splitter is a dc-4.
 

olds

Elite Member
Mar 3, 2000
50,122
778
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So, I need a couple of splitters to rewire. Are the Radio Shack "Gold" ones good enough or should I get something else?
Example?
I may also get a powered splitter after I rewire if the signal is weak.
 

erwos

Diamond Member
Apr 7, 2005
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Originally posted by: oldsmoboat
I may also get a powered splitter after I rewire if the signal is weak.
If it's an option, always use powered splitters. Digital QAM is much, much more sensitive to signal loss than analog is.
 

olds

Elite Member
Mar 3, 2000
50,122
778
126
Originally posted by: erwos
Originally posted by: oldsmoboat
I may also get a powered splitter after I rewire if the signal is weak.
If it's an option, always use powered splitters. Digital QAM is much, much more sensitive to signal loss than analog is.
I am assuming I should split after the modem?

Main line - splitter - modem - powered splitter - tv - tv
**********/
********HDTV