We have many TV’s hooked up to the cable system. Only one has a digital converter. We do not get the digital stations we are supposed to. They came out and trouble shooted and said the cable in the house was not allowing the digital signals to reach the converter box. Now my wife has noticed that large numbers of channels that the other TV’s get are unavailable on the one with the digital hook-up? I can understand not getting the digital channles because of some cable problem, but why can we not even get some of the stations that the other televisions do? Is there a way to fix this?
It may be that the signal strength is low because you’re splitting the signal too many times. Do you have an amplified splitter (one that plugs in to an electrical outlet), or just the simple kind? One thing you could do to test this is to remove the splitters, and send the signal to only the converter box. If it works then, then low signal strength is probably the problem, and you’ll need to get an amplified splitter (about $20 or $30, IIRC). You’ll need to find out how high of a frequency the cable uses, and make sure the amplifier works that high. If it still doesn’t work, can you temporarily move the TV and converter box to where the cable first comes in the house? This removes all the house cable wiring from the equation.
(Actually, it’s possible one of your splitters (or even the cable) only work up to 1000 MHz, and that the digital channels are higher.)
I ran into this problem when helping run cable at my in-laws’ house. I needed another splitter, so I got a cheap one from WalMart. All the TVs worked, but I couldn’t get the signal to the cable modem. I happened to think to compare the splitter I bought to the ones the cable company installed and I noticed that my splitter wouldn’t pass the same frequencies the cable company’s splitter used. Maybe your digital box is having the same problem.
Could also be a bad inside run just to that TV. What happens if you take the digital cable box to one of the TV’s that’s getting more analog channels?
Also, if you can get to the cables without having to tear walls apart, make sure that all of your cable is labelled RG-6 instead of the older RG-59. This can cause some problems.
But I concur with the others that the problem is most likely with the splitters you’re using.
It does have an amplifier, plus splitters, all installed by comcast. I will check and see if I can find the Mz information though. And I am almost positive the cable is the older RG-59.
My guess is you’re in an area using something called digital overlay, where if you use a digital cable box, all channels, even the ones you can receive in analog, are tuned in using the digital signal. Your signal is strong enough to get a watchable analog picture on your other TV’s, but weak enough that the digital box just says “nope” and refuses to tune to that channel.
I’ve had this happen. Rewiring with better quality coax for part of the run, and replacing a passive splitter with an amplified one fixed the problem, for the most part.
I’d be surprised if Comcast allowed RG-59 to be left in service. Around here, they require not only RG-6, but RG-6QS. The QS means quad-shield - four layers of braid and foil guaranteeing 100% leakproof cables - nothing can leak out or in. RG-59 hasn’t been suitable for use in a cable TV system for over 20 years as it leaks far too much signal.
As for splitters, the bare minimum these days is for the splitters to be rated for 1000 MHz / 1 GHz. The better splitters now will pass 2 GHz or more.