Advice on improving cable TV signal

[donheff]

Once again time to appeal to the knowledgeable among us. I have a cable TV problem. I have a TV in the kitchen fed by an old coaxial cable that was installed when we had an addition put on about 20 years ago. That TV does not get all the channels that other TVs do. The Comcast guy who evaluated everything and replaced a couple of my old splitters in the basement concluded that the cable itself is problematic. Lots of noise, low signal at the TV - decent signal at the splitter. I am gearing up for a trip into the claustrophobic crawl space under the kitchen to fish a new cable through the wall and across to the splitter but before I do...

Any particular cable I should get? I would be inclined to get any old good deal available on 75 ohm coax. Also, would a signal booster be an alternative to fishing new cable? Do those things really work and, if so, what kind should I try?

By the way I talked to Comcast about cable maintenance plans and learned that all they cover is external cable (e.g. a line they ran around the outside of your house and passed through a hole in your wall). They don't deal with internal wiring. I can't understand why they even offer such plans. Maybe people assume they have something valuable untill the need service. I pay for and actually get inside maintenance from the phone company.

Also, ironically, the troublesome cable was professionally installed when we had the addition built. The rest of the house has my older, half as*ed cable plant strung up the outside wall, thru an attic vent, down through the walls, crimped with pliers... Three TVs on that cable plant working fine.

 

[RockyMtn]

do you have a cable box on the tv? It is possible that the reason it's not getting all of the channels is that they have switched a number of signals to digital and if you are feeding the tv directly you would likely only get the analog signals. Also, how old is the tv?

 

[MichaelB]

Have you ruled out the tv? Does that same tv get more stations when connected to another outlet in the house?

Edit - cross posted with Rockymtn, but we're both thinking along the same line.

 

[RockyMtn]

Wouldn't waste my money on a booster. Usually cable lasts a pretty long time. Maybe it got knawed on by something If you do need a new piece of cable any RG59 75ohm coax should work.

 

[donheff]

I should have filled out additional data. I have a Comcast cable box on here (one of the little ones, not a DVR). The TV is a new, small, flat screen and works fine. I replaced the cable box three times thinking that was the problem. Twice that improved things briefly but it quickly deteriorated. The third time there was no improvement. The Comcast tech said the signal at that end of the cable is way below spec. Replacing the splitter that feeds that segment didn't help although dropping the other segment fed off that line improved the signal enough to make a difference but not cure things entirely IIRC.

Edit: I get most stations but some drop off. For example in the cable news area I get MSNBC and Fox but I don't get CNN and MSNBC now comes in with video but no audio. The cable guy said a weak signal can cause all of these symptoms.

 

[RockyMtn]

If the signal drop off is a relativley recent occurence it is probably the cable. If this location has given you problems for 20 years it may be too far of a run from the main drop or your signal is split too many times. Done any nailing in the area? I have seen nails go through RG59 and really screw up a picture.

I suggest you buy a new chunk of cable and bypass the old cable running it overland from the splitter to the tv. Check the picture...if its good then you go to the effort of crawling under the house. Good luck.

 

[MichaelB]

Usually a low signal affects more than one tv. Have you tried disconnecting the spliter and all other units and connecting the other end of the kitchen line directly into the source. If it is signal strength you should see an improvement.

 

[donheff]

Wouldn't waste my money on a booster. Usually cable lasts a pretty long time. Maybe it got knawed on by something If you do need a new piece of cable any RG59 75ohm coax should work.

Oh no, that could be it. Once of the reasons I don't want to go down there is it became a rats nest at one point. The story about how I got rid of them is awful - definitely not fit for a family forum like this. Luckily, as the upshot of that period I had a concrete slab poured in there (quite another experience). So at least now I can crawl around without my knees breaking into tunnels

 

[donheff]

Usually a low signal affects more than one tv. Have you tried disconnecting the spliter and all other units and connecting the other end of the kitchen line directly into the source. If it is signal strength you should see an improvement.

See my additional comments (ours posts probably crossed). Isolating other segments does improve the signal somewhat.

 

[MichaelB]

I suggest you buy a new chunk of cable and bypass the old cable running it overland from the splitter to the tv. Check the picture...if its good then you go to the effort of crawling under the house. Good luck.

This is a good idea. Just do a direct connect in the house with run as long as the one installed. That will tell you right away if it is signal or cable.

 

[donheff]

I suggest you buy a new chunk of cable and bypass the old cable running it overland from the splitter to the tv. Check the picture...if its good then you go to the effort of crawling under the house. Good luck.

This is a good idea. Just do a direct connect in the house with run as long as the one installed. That will tell you right away if it is signal or cable.

Good idea. I just had one of those duh realizations. It is less than 25 feet from the basement splitter to the TV through the crawl space and walls but would be about 40 or more feet running it through the basement and the stairs to test it. The duh was the realization that I can just connect the 25 cable to the splitter and take the TV and cable box downstairs to test. You can see why I ask for advice -- it would be just like me to get a 50 foot cable to test and only think about moving the TV after I went to all the useless trouble.

 

[MichaelB]

25' or 40' shouldn't make a difference - both should be good. This is sounding like bad cable.

 

[ls99]

Wouldn't waste my money on a booster. Usually cable lasts a pretty long time. Maybe it got knawed on by something If you do need a new piece of cable any RG59 75ohm coax should work.

Rg59 is a bit lossy at cable trasmission frequencies. Most cable companies use RG6. If you do your own get good quality type F connectors. Or you might pay some independent cable guy to install the connectors. Pulling cable can be dirty and time consuming, good DIY. If you screw up the connector install, you will pay someone to get it right. Bad connector install can result in 100% signal loss. Each connector can loose 3 to 6db of signal.