Grainy TV pictures

I have cable TV. Most of the channels are very sharp and clear but there are a few where the picture is quite grainy. Unfortunately some of these grainy channels are my favorites, like the Sci-Fi Channel. I’ve called the cable company several times about this problem, but when the techs come out and run tests, they always say that the signal is “within specifications”. Well, sorry, but that’s not good enough. Some of my favorite shows are ruined for me by the bad picture.

To the cable company’s credit, they have gone so far as to replace the cable line to the house and installed various signal boosters, but without effect.

Anyone have any ideas about what I can do to solve this problem?

Cable TV engineer here.

Sounds like the people who came out to do tests didn’t do the tests properly, or didn’t do the correct tests. (I certainly am not impressed by their customer service - why tell you the signal is OK if the picture is patently not OK?) It may be that they just measured the incoming signal levels. Yes, there are minimum and maximum signal levels specified for cable TV systems, but there’s more to getting a good picture than just getting the levels right. Most likely there’s one or more amplifiers in the cable feed that are either faulty, or being over-driven (or under-driven). Getting acceptable pictures at the far end of a cable, with possibly several amps in cascade, is not a trivial task (though professional cable TV engineers ought to be able to do it). Certainly just installing amps in the feed won’t help if the carrier/noise ratio is too low - you end up boosting the signal but also the noise, and you still get grainy pictures. Did they do CNR tests on the faulty channels?

Replacing the cable sounds like desperation - although a damaged cable can cause frequency-dependent losses which will affect some channels rather than others, a TDR test would establish whether the cable was in fact damaged or not. (If they don’t know what a TDR test is, I despair.) If the test revealed no damage they wouldn’t need to change the cable, and since replacing the cable had no effect I presume it was in fact undamaged.

I suggest you find a trustworthy TV engineer and show them your pictures. Then get him/her to call the cable company on your behalf. A cable specialist would be ideal, but you at least need someone who can recognise incompetence or bullshit when they hear it. Good luck.

I had a different problem, but only through persistence and writing the CEO of Cox did I eventually get it fixed.

It was an intermittent problem where every now and then I’d lose my broadband connection completely. I’d then check the TV and find all the channels were really badly snowy, but still there.

So, would call the techies, and eventually somebody would come around and tinker. It would be OK for a while, then happen again.

This went on for a few months, and technicians came four times, each time doing some different, still no permanent fix.

So, finally sent a polite but very firm letter, pointing out what happened, and demanding that i get a credit for all the time I did not have service.

Finally somebody came, checked the cable into the house, and lo and behold, on both ends the central pin on the connector was not long enough. He replaced both connectors, and it has been just fine ever since. I also got a credit on the next bill.

You gotta be persistent and keep insisting they fix it until they do (maybe).