Coaxial Cable Junction Box/Split

apriest · 07-21-2009, 07:56 PM

Hello everyone! This is my first post on DIY Forums...I only recently discovered all of you and this is amazing.

Anyways - I'm trying to help my mom upgrade her Comcast service to include digital TV, Internet, and Phone. The serviceman said that the quality of the signal running to the cable outlets was very poor. We tried to locate the junction box or split point where the origin line branches out but there doesn't seem to be one. We identified the source line that runs from outside but it seems to run into the attic over the garage and it disappears above the master bedroom. But there is no panel or access to the cable that we can locate. The house is a townhome, relatively newer construction (she's been here for 7 years and is the first to occupy), but I get the feeling that the contractor was less than exemplary.

There are no shared boxes (like in an apt setting). Is it possible that the contractor just split the coaxial cable as he went along and then buried them in the walls??? Ugh.

Thoughts on this? Any solutions that don't involve fishing through the walls? Maybe a signal booster?

Sorry for the lengthy post...and any insight is GREATLY appreciated.

Best.

220/221 · 07-21-2009, 08:11 PM

You have one cable going in and several cable openings inside?

If they split inside, they generally do it in the walls behing the cable jacks.

If they did it in an inaccessible attic space or closed in wall cavity, you are screwed and need to run new cable.

Sometimes it's easy, sometimes it aint.

jerryh3 · 07-21-2009, 08:14 PM

Take one of the cable plates off and see if they used splitters inside the boxes. Also, what do mean the cable disappears above the bedroom? Does it run down into a wall from there? How many rooms would she like the tv to be in? Where would she like the cable/phone modem?

apriest · 07-21-2009, 10:16 PM

Thanks for the responses! Sorry for any ambiguity. The source cable runs from outside across the garage attic and into the wall behind the master bedroom. I cannot locate any splits before that point so obviously the splits were made in the wall cavities (which makes my life fun).

She wants tv in a loft on the second floor and in the master bedroom on the first floor (which is almost below the loft). The cable/phone modem would ideally be with that upstairs connection in the loft.

Since the issue is low signal quality, is it possible that a short-term fix would be a signal booster/amplifier? At least enough to tide her over until I can tackle the larger project of running new cable in a logical fashion?

Thanks again.

gregzoll · 07-21-2009, 10:28 PM

Not with Digital Cable. If there is poor signal quality, get CC to come in and look at it. They have the tools & testing equipment to determine.

kbsparky · 07-22-2009, 05:15 AM

Digital cable service requires separate lines for each jack. This includes internet modems, and VOIP devices.

williswires · 07-22-2009, 08:53 AM

Your cable modem should get it's signal from the very first splitter. Anything else is a degraded signal and will give you problems/internet connectivity issues.

The incoming cable needs to go to high quality splitter as it comes in the house from Comcast. One output goes to the cable modem, the other output serves the rest of your installation.

jerryh3 · 07-22-2009, 09:05 AM

Where are you located?

apriest · 07-22-2009, 10:46 AM

This is all great information. The CC guy is supposed to return today so having this knowledge will be very useful, even if it painting a bleak picture for the work I have cut out for me!

I am located in Northwest Indiana.

J. V. · 07-22-2009, 12:00 PM

You could try an inexpensive amplifier at the TV furthest from the source signal. If it works better you can install them at every point of use, if needed. They run under $25.00 each and need a 120 volt receptacle.

gregzoll · 07-22-2009, 11:14 PM

It can still be daisy chained, and does not require Ethernet or voip if you think that is what it is called. You really need to read about the technology before just posting FUD.

gregzoll · 07-22-2009, 11:15 PM

You cannot use amps with Digital cable.

gregzoll · 07-22-2009, 11:16 PM

A cable modem is only used to connect your computer, and yes it can be placed at the head of the line not 6 split lines down. May still work, but not in the best quality.

InPhase277 · 07-22-2009, 11:36 PM

Well, let the other TVs have crappy signal. Go back to the garage attic where you have verified the cable is unspliced, and splice it there. Use the good compression connectors and do a good job. Run a line from there to the spot where you want the modem/phone and new TV.

Better yet, run a new line all the way outside, with no splices.

Scuba_Dave · 07-23-2009, 08:35 AM

When my digital went in they ran a line to the basement
Big old UPS/combined system installed for phone/cabel/Internet
From there to a splitter - 1st line from splitter had to go to the cable modem
Then other lines to each TV, not daisy chained
Since I'm remodeling I'm running new/more Quad 6 runs thru-out the house
Plus phone & CAT6 runs

They should run a new main line to a central location
After that it is your cost of they run more
I had one TV that had poor pircure - it had a splice in the line, older cable
I ran a new line & the picture is much better