S3 Pixelization/Houston -- anyone else still having problems?

The problem is still there for me. I don't know the root cause (I have my theories), but I can observe fluctuating signal strength, and when it falls below a certain point the breakup starts.

The first thing I did was replace all the splitters I was using with a distribution amp which instead of degrading the signal gives it a boost of 4-5 dB at each outlet. This made a marginal improvement. It is marginal because when the signal drops, it falls off a cliff. Sometimes I even get an "off air" message on the screen.

Like others, my worst issue is with NBC and ABC and their associated channels. With football starting I popped into RadioShack and grabbed an indoor antenna (15-2186). It is working better than I had expected. On CBS the signal is actually stronger than the one from Comcast.

PBS and ABC have a weaker signal than the others and are subject to very infrequent and very brief breakups. It may be coincidental, but they are both on the same tower while almost everyone else is on another tower. From my location they are only a couple of degrees apart and the antenna seems to be pretty omnidirectional. In addition PBS is broadcasting on VHF; it must be lonely there. They are having other problems as well, as evidenced by the abandonment of HiDef. Maybe they cut the transmitter power to lower the electric bill .

Now, since my TiVo is analog and not digital, I can positively state that this issue arises with no TS3 or THD present. And since the issue is present when I bypass the CableCARD in my TV I can state positively that the issue arises with no CableCARD present.

I wanted to stick a Comcast box in the mix but they have been out of STBs with HDMI for weeks and there are a lot of people in the que ahead of me. I don't want Comcast to roll a truck until I can see whether the issue is still there when tuning with Comcast equipment.

At some point I hope to be able to show Comcast that they are not providing me a consistent signal and that they need to find the reason.

There is also another thread on this...
http://www.tivocommunity.com/tivo-vb/showthread.php?t=359773

Someone a lot smarter than me posted what the reason was in a past thread. From memory, it was related to Comcast adding the new HD channels this summer. When they did, they crammed more signal in the same amount of pipe, and created some "instability" in the feed (my word, not the smart guy's). He even figured out which channels were on which part of the pipe and was able to show that ABC/NBC (among others) was in this specific bandwidth that was causing the problem. This was for our specific area. Other parts of town might have a similar problem, but different channels.

This instability can cause problems in some equipment, but not all. And cablecard equipment seems particularly vulnerable. That's why you rarely hear about this with their DVRs. I have an SA8300HD, and it almost never has pixellation. I also had my S3 for 8-9 months without any problem, and within days of Comcast adding channels, up pops my problems (and everyone else's). That's why you never heard about this prior to the last few months.

Because the problem is signal related, minor ancillary problems can set it off. If you have perfect cabling (new RG6) and high quality splitters, you may never see it. Older houses (I have RG59 from 20 years ago) may be enough to trigger it. Sometimes an amp helps; other time not. Or who knows *what* the exact tipping point is?

Since it rarely affects cable STBs or DVRs, Comcast finds it easy to ignore. But the fact that some S3s are immune, and others aren't, and that changing cablecards doesn't fix it, pretty clearly shows it to be a signal problem, and not a pure TiVo problem. But until Comcast makes some type of major change in their signal distribution system, I think we are just SOL.

Yeah, I'd love to see our price increase go to fix this

golubian said:

Comcast tech came out today. He got someone at the Comcast mother ship on the line via his radio (I could hear the conversation), and the mother ship absolutely, positively insists that this is a Tivo software issue, confirmed by him during a four hour phone call he claims to have had with Tivo. I repeatedly told the tech that this was an S3, not the HD Tivo for which Tivo had conceded there was a software problem. Comcast mother ship nonetheless insisted that Tivo had confirmed to him that the pixelization on the S3 is a software problem known to Tivo.

I'm not sure who or what to believe. I have to think that it's a combination of things, given that in the Houston area this problem appears generally limited to a few discrete channels that many of us are having problems with. I can't really think why Tivo's software would have no problem dealings with all the other HD channels, but for some reason have a problem showing the local ABC and NBC affiliates.

Click to expand...

That's just it. It's channel specific. If it was a TiVo problem, like it was with the HD and SA cablecards, I would expect tiling across additional channels. But it's tied to certain channels, and also, it's very intermittant.

I live in Cypress, NW Houston. When I first hooked up my S3 units, all was fine. Then maybe a month or so later, I get tiling on Nick, Speed, HGTV, maybe a couple others. But none on the local HD channels, none on Discovery HD, etc. At this time some other folks around Houston are having tiling issues on their local HD channels, but no problems on Nick, Speed, etc.

It seems regional. My Mom, who lives like 7 miles away, problems with same channels as me, but not local HD channels like others.

I thought at the time that we were looking at too many channels riding together on a single frequency. I don't pretend to understand it, but some frequencies were "crammed" and I think Comcast was not aware of how their channel distributions affected cablecard devices. I had a cablecard TV (with no TiVo) and it suffered with this issue as well.

I worked with Comcast extensively, they never blamed the TiVo (probably because I had a TV without a TiVo doing the same thing), but could not get it resolved either. I was prepared to cancel Comcast service and let them know. Then my problem channels cleared up all by themselves.

I was fine ever since, then a few weeks ago, I started getting tiling on the locals like other folks in Houston. Never had problems with these before. For a couple of days, I just used my OTA antenna for these channels (with no problems). The problems with the locals over cable went away in less than a couple of days, and I've been completely fine since.

I think Comcast is figuring out the impact of their channel/frequency distribution on cablecard devices, and they are now understanding that their adjustments might have a negative impact. My stuff has stayed consistent, but I think they are shifting things around. I'm not too worried about it though. Since July 1st, they have had to start deploying cablecard STB's, so I think cablecard understanding and support in general is going to get better.

But in the end, I'm glad to have an OTA antenna as a back-up.