Augh - glitches every 5 minutes, TWC NYC

Discussion in 'TiVo Series3 HDTV DVRs' started by Ian, Nov 20, 2009.

  1. Ian

    Ian TBLBITW

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    Mar 7, 2000
    NYC

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    Hi-

    Just got a new TiVo XL, one M card.

    On several stations tonight, glitches every 5 minutes... pixelization and audio dropouts.

    This happened a year ago when I tried HD, I truly thought it would be fixed by now.

    I have excellent signal... what the heck is causing this, and is there anything I can do?

    Thanks!

    -Ian
     
  2. dlfl

    dlfl Cranky old novice

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  3. bkdtv

    bkdtv New Member

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    Has your TiVo upgraded to the latest 11.0d software yet?

    Out of the box, a new TivoHD XL would be no different from a year ago because it ships with the same software.
     
  4. Ian

    Ian TBLBITW

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    Hi-

    I DO have 11.0D... not sure if it's the very newest version of it though - what's the latest version number?

    Thanks!

    -ian
     
  5. dlfl

    dlfl Cranky old novice

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    11.0d is the latest (as bkdtv said in his post).

    Also, bkdtv's sticky thread on TiVo Overview, ..... (at the top of this forum) is highly recommended -- better than the TiVo User Guide.

    Tune to 1 (or 2) of the "bad" channels then go to Messages & Settings .... Account & System Information ... DVR Diagnostics. What is (are) the signal strength (s) for the tuned channel(s) ? Too hot a signal can cause glitches like yours. These readings are limited to 100 so if it's above 100, it still reads 100. There are inexpensive in-line attenuators you can get to reduce the strength. Also look at the SNR and RS Corrected and RS Uncorrected signal counts. Ideally both RS counts should be zero. If you have RS Uncorrected counts that are climbing rapidly that indicates a signal problem, perhaps too hot, or a bad connection, cable or splitter. Check the counts before and after a glitch. They are cumulative starting from the Tune Start time.
     
  6. Ian

    Ian TBLBITW

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    Dlfl...

    Aha! Actually, my signal strength readings this morning were showing 100, so I wouldn't be surprised if there WAS a "too hot" signal coming in,

    I also did look at the RS corrected and uncorrected errors... on Thursday I saw zero, this morning I was seeing numbers in the hundreds and thousands.

    I'll look into the attenuator thread right away.

    Thanks!

    -Ian
     
  7. Ian

    Ian TBLBITW

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    Hi again-

    It looks like the attenuation fix was developed for FIOS customers - anyone know if it works with Time Warner as well?

    Thanks!

    -Ian

    (also, anyone know where I can physically buy attenuators in NYC?)
     
  8. dlfl

    dlfl Cranky old novice

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    I'm pretty sure some non-FIOS users are using attenuators.

    I bought mine on-line (not currently using them). Just Google "cable attenuators" and several sources including Amazon will be found.
    I think I got mine from here:
    http://www.hometech.com/hts/products/video/attenuators/index.html

    Recommend an assortment of say 3, 6 and 10 dB. You can cascade them if necessary, i.e., 10 + 6 = 16. TiVo recommends signal strengths in the range 80-99.

    About 1/3 of my channels are slightly above 100 because if I attenuate them down to 99 or less, the weak channels end up at 68, which isn't ideal. Splitters can be used as attenuators. A 2-way will be 3-4 dB.
     
  9. Ian

    Ian TBLBITW

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    Hi again-

    I wandered the city today looking for attenuators - no luck, of course, I will have to order online. But I did totally randomly run into a Time Warner tech on the street and he gave me a -8DB splitter that he terminated on one end for me.

    I've installed it now and it's definitely knocked down my signal strength - I'm seeing nothing stronger than 93 now - unfortunately, a few stations have been knocked all the way to the mid 60s, which isn't ideal...

    I've been testing out a bunch of the movie channels, and they all seem to have signal in the high 60s, SNR between 31-35...

    But already, even with those numbers, I've noticed glitches on two stations out of 20.

    Guess we'll have to wait, see, and do more testing...

    -Ian
     
  10. dlfl

    dlfl Cranky old novice

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    Sounds like a 3 dB might be optimium for you. It should get the minimums up to 80 and the strong ones will be slightly over 100, which I think is OK based on my experience.

    I still get occasional pixelation on some channels and I think many others do too. I have SDV and thus use a Tuning Adapter. The channels with the most pixelation are SDV channels for me.

    Note that if your RS Uncorrected counts are zero or only a few hundred and not increasing, that is supposedly the whole story. You are receiving the digital signal exactly as it was encoded. The pixelation I see is with zero RS counts.
     
  11. Ian

    Ian TBLBITW

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    I guess I'm going to have to order the attenuator pack - just noticed some major glitching on a station in the mid 60s...

    So, are you saying that those glitches should go away if I can get the signal up into the 80's, maybe with less attenuation?

    Thanks-

    -Ian
     
  12. dlfl

    dlfl Cranky old novice

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    All that can be said for sure is 80-99 is best. If you read what I said above about RS Uncorrected counts, it follows that you can have pixelation for other reasons than just signal strength problems.
     
  13. Ian

    Ian TBLBITW

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    Thanks dlfl - I didn't actually understand your last post about the RS Uncorrected.

    So, the anntenuators should theoretically fix the RS Uncorrected problem causing glitches.

    Any OTHER glitches are due to ... something else.

    Do I have it right now?

    Thanks!

    -Ian
     
  14. dlfl

    dlfl Cranky old novice

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    What are your RS Uncorrected counts doing now on the bad channels? If they are zero or only a few hundred, and are not increasing, then as I understand it you are already getting a perfect signal and fiddling with attenuators should not help.

    If the counts are not zero or low, finding the best attenuation may fix them. Other problems can also cause weak or noisy signals.

    Even if the counts are zero or low you can still get pixelation because it's actually in the signal as decoded by the TiVo. There is a theory that signals that don't cause pixelation with cable co. STB's or VCR's can cause it with TiVo decoders because the decoding parameters and/or circuits are not identical.

    In summary it's complicated, not well understood, and kind of a crap shoot. You will find plenty of complaints and discussion about pixelation on these forums but there are also many users who either have no pixelation or who can live with what they do get. I'm trying to convince myself I can live with what I get. I've made a study of it including reading this forum very carefully and there is no simple answer.
     
  15. Ian

    Ian TBLBITW

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    Thanks, I get it now...

    I'll watch for glitches and see if when they occur, I'm getting uncorrected errors - I have a feeling that IS the case here, but we'll have to see.

    I'll report back when I know more, thanks!

    -Ian
     
  16. Ian

    Ian TBLBITW

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    Crud...

    I'm still getting glitches with 0 uncorrected and 0 corrected errors, on a channel with signal strength in the mid 80s.

    Oh, well...

    -Ian
     
  17. dlfl

    dlfl Cranky old novice

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    How about your local broadcast HD channels (ABC, NBC, etc.)?

    It's rare to get pixelation on those channels (with zero error counts). If you do then the possibility of a bad hard drive needs to be considered. Tune to two HD channels that don't have pixelation and play back a recording of an HD channel that doesn't have pixelation. 1080i channels are preferable for this. This maximizes the disk read/write workload and tends to expose failing drives by showing pixelation and other problems such as slow menu response.

    Do you have a tuning adapter?
     
  18. Ian

    Ian TBLBITW

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    Mar 7, 2000
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    Hi there-

    The pixelization (even with the error counts of zero) seems to be happening on my movie channels only... the shows I've been watching on broadcast networks seem to be OK so far.

    No TA needed, in NY we don't have SDV.

    Besides the attenuating, is there anything I can do? Can Time Warner literally change my signal for the different channel blocks? Is that something they even do?

    Gosh, I'm so totally frustrated with this... and thank you for your continued help.

    Off to the gym for a bit!

    -Ian
     
  19. dlfl

    dlfl Cranky old novice

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    How bad is your pixelation? Is it constant or in spurts? How often are the spurts? How bad is the picture breakup? Any freezes?

    In principle you should "go through channels" on this, i.e., call both TWC and TiVo support and see what they can do. The worse the pixelation, the more likely they are to be motivated, I think.

    Yes TWC can adjust signal parameters. However you have to keep in mind that TiVo digital users are only about 0.5% of the national digital subscriber base. I think the obviously reasonable assumption is they adjust their parameters for good performance on their STB's and DVR's. If a channel looks bad on those, they get massive complaints. Not only is there little motivation to adjust also for good TiVo performance, but it probably is technically difficult for them to do that -- I bet they don't even have a TiVo in house to use for testing. TiVo users are just a thorn in their side -- they would be happy to see us disappear.
     
  20. Ian

    Ian TBLBITW

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    Mar 7, 2000
    NYC
    Hi all-

    Just an update...

    I've been writing down the numbers of the channels that glitch and those that don't, and the "good" channels outweigh the "bad" ones about 5 to 1 so far...

    ...and it seems that nearly all of the "bad" channels are HD premium movie channels. The regular broadcast networks and basic cable channels are MUCH less affected.

    Not ideal, considering that the TWC box doesn't glitch on ANY channel, but still a lot better than I feared originally.

    (Mind you, on the bad channels, it's still showing corrected and uncorrected errors at zero.)

    My attenuator pack is coming in today, so I'll remove the -8DB splitter and try a -6DB attenuator - maybe THAT will tweak the signal the extra bit to cut down the glitches on the movie channels.

    have a great day-

    -Ian
     

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