A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » General Hardware & Peripherals » General
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Split Cable Modem Line For TV Tuner?



 
 
Thread Tools Display Modes
  #1  
Old November 22nd 03, 04:27 PM
*Vanguard*
external usenet poster
 
Posts: n/a
Default Split Cable Modem Line For TV Tuner?

Some Guy wrote:
Hi,

I'd like to know what problems to expect if i try to split my cable
internet line right before the modem to accomodate a new TV tuner
card.

My line looks like this:

CATV Jack - Cable Company Installed Splitter:
Splitter output 1 goes to my TV in the living room (which I will
split to reconnect the upstarirs TV in the master bedroom.
Splitter Output 2 goes on a long journey to my room to my modem. I'd
like to split this line just before the modem and have:
Splitter 2 - Output 1 to Modem, Output 2 to Tuner.

What can I do to keep signal strength up?

I also plan to install a switch to run my internet to a second
computer.

Thanks,
Jesse


The 2-way splitter installed by my cable company (since I have both
cable TV and broadband Internet services) has the following markings:

5-1000 Mhz
120 db EMI isolation
3.5 dB (on each "out" tap)

Don't get more splits than you need. That is, don't get a 4-way
splitter when you only need 2 splits and think that putting a 50-ohm
screw-on terminator on the other unused taps is okay. Just get a
splitter that does minimally what you need. Pretty much this looks to
be equivalent to the type of 2-way splitter you can get at Radio Shack
(http://snurl.com/rs2waysplit).

I have a Motorola Surfboard external cable modem. I can see its admin
page by browsing to http://192.168.100.1/. By going to the Signal page
I can see what are the downstream (PC side) and upstream (provider side)
signal strengths. Currently I have 5 dBmV on the downstream side and 45
dBmV on the upstream side. You will be installing the splitter on the
upstream side. If you can get a similar page (or utility to show this
info) then check the upstream signal strength at the cable modem before
and after installing the 2-way splitter. This will let you know how
much the signal got attentuated to the cable modem. If you use an
amplifier, you can also check the upstream signal strength at the cable
modem. To low a signal and you'll have problems but also too strong a
signal can cause problems (at one time my cable company actually had to
insert an attenuator to bring down the signal strength to eliminate
problems; the symptom was too many lost packets but the cause was too
strong a signal).

According to the article mentioned by Stephen, the 3.5 dB attenutated
output taps will reduce signal strength by 56%. If your cable modem has
a web page or utility to show its diagnostics and to show signal
strength then you can verify if it this actually happens in your
scenario.


--
__________________________________________________ __________
*** Post replies to newsgroup. E-mail is not accepted. ***
__________________________________________________ __________



  #2  
Old November 23rd 03, 12:38 AM
DaveW
external usenet poster
 
Posts: n/a
Default

If your cable company has decent signal strength, which most do, you should
easily be able to split the signal at your computer based on how little else
is hooked up in your house.

--
DaveW



"Some Guy" wrote in message
...
Hi,

I'd like to know what problems to expect if i try to split my cable

internet
line right before the modem to accomodate a new TV tuner card.

My line looks like this:

CATV Jack - Cable Company Installed Splitter:
Splitter output 1 goes to my TV in the living room (which I will split to
reconnect the upstarirs TV in the master bedroom.
Splitter Output 2 goes on a long journey to my room to my modem. I'd like

to
split this line just before the modem and have:
Splitter 2 - Output 1 to Modem, Output 2 to Tuner.

What can I do to keep signal strength up?

I also plan to install a switch to run my internet to a second computer.

Thanks,
Jesse




  #3  
Old November 23rd 03, 08:07 PM
Todd H.
external usenet poster
 
Posts: n/a
Default

"Some Guy" writes:
Hi,

I'd like to know what problems to expect if i try to split my cable internet
line right before the modem to accomodate a new TV tuner card.

My line looks like this:

CATV Jack - Cable Company Installed Splitter:
Splitter output 1 goes to my TV in the living room (which I will split to
reconnect the upstarirs TV in the master bedroom.
Splitter Output 2 goes on a long journey to my room to my modem. I'd like to
split this line just before the modem and have:
Splitter 2 - Output 1 to Modem, Output 2 to Tuner.

What can I do to keep signal strength up?


A high quality splitter, high quality cables, and proper termination
of all signal lines (e.g. don't leave one unconnected after the
splitter).

Aside from that, there's really no way for anyone here to tell you
what to expect aside from that, as it depends on the strength of the
signal at your particular house. Odds are, it won't cause a
problem..and if it does, it's trivial for you to undo the change and
divine another way to drag cable to your TV tuner card.

Best Regards,
--
Todd H.
http://www.toddh.net/
  #4  
Old November 23rd 03, 11:14 PM
CBFalconer
external usenet poster
 
Posts: n/a
Default

Some Guy wrote:

I'd like to know what problems to expect if i try to split my
cable internet line right before the modem to accomodate a new
TV tuner card.


A properly matched passive splitter has a 50% loss from any port
to any other port. For cable internet you have to feed both ways,
so you need passive splitters. All 3 ports on a properly designed
passive splitter are equivalent, and all three should feed
properly terminated lines.

--
Chuck F ) )
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net USE worldnet address!


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
name of cable from DSL modem to network card ? Marcel Verduyn General 4 October 21st 03 05:57 AM
Cable modem problem [email protected] General 1 September 25th 03 09:16 AM
Dial up modem problem Richard Freeman General 21 September 22nd 03 05:50 AM
Power Surge David LeBrun General 44 September 12th 03 02:35 AM
fax/adsl modem 123xxxxx General 41 August 3rd 03 09:37 AM


All times are GMT +1. The time now is 07:51 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Copyright 2004-2022 HardwareBanter.
The comments are property of their posters.