06-24-2011 12:06 AM
I got the DTA box for the tv in my room as some channels were not coming in and it said I needed the box to view them. I then set up the box and some channels showed up, but a majority did not, such as my local channels. I unhooked the box and just used the cable until the past week where even my local channels would not work without the DTA box as it said on the screen. So I hooked up the DTA box again and still do not get a majority of the channels, instead I get a black screen with the phone number for Comcast. I have another DTA box in another room with another TV that gets all the channels perfectly fine. I was wondering what could be causing this? Any help is greatly appreciated!
06-24-2011 12:20 AM
It is most likely signal issues to that TV outlet. Weak signals from too much splitting or splitters wiring arranged wrong. It is more common in older homes which many times the wiring and splitters are "daisy chained" instead of current ways of running "home run" to each outlet.
It can also be as simple as damaged coax to that outlet, loose / corrorded F connectors, or other workmanship issues.
In the past on analog systems, weaker outlets would just show up as "snow" or a more poorer picture and the signal frequencies topped out at 550mhz. In digital systems, the frequencies are carried up to 750 or 860mhz, old splitters are left in the house that will not carry the higher frequencies, and coax cable has more loss at the higher frequencies. F connector fittings are more critical that they are installed properly and are compression fittings.
Digital tuners need a good signal level from around -10 to +10 to operate properly. It is common for levels at the TV outlets in older installations to be too low for these higher digital channels.
You should either try to eliminate any excessive splitters in the home, check workmanship of the coax installation and that all fittings are attached firmly. Check all splitters will pass 5mhz - 1002mhz.
You might need a tech out to find and fix the signal issues, as the tech will have the proper tools and test equipment to check the levels at each out across the complete band of frequencies.
It could also be signal issues coming into the home that end up with poor levels at the outlets. A pro with the proper equipment will find it. If it is inside wiring issues, and the wiring is owned by the homeowner, you might get a charged a flat rate charge to repair your wiring. Only a tech can decide if it's inside or outside.
06-24-2011 10:58 AM
Thank you for the response. I am not the most technically gifted person so can you explain to me what I can do myself to check if it is one of the solutions you offered before I have to have to have someone come out? Thanks!
06-24-2011 07:14 PM
The only thing you can do is check that your F connectors are snug at the wall outlets, back of the box at any splitter, fittings are attached onto the coaxial cables firmly, and no damage to the coax. Wiggle around the coax at the connectors if anything improves.
Otherwise you need a expert with the right tools and test equipment to find where the loss is and the signal levels are at each outlet. Digital signals levels are critical and need to be between withing specs for the boxes to work. Because everyone's coaxial cable wiring is different in each home, knowledge of workmanship, splitter & coax loss and best practices is needed to supply each outlet a good quality signal.
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