Originally Posted by jcanyon
I have two TiVo Series 4 DVRs and a cable modem connected in my home. I have been experiencing pixelation on my time warner cable on many channels.
My s/n ratio (Settings, DVR diagnosis) showed a S/N ratio of 36/37 The Tivo folks told me to have TWC reduce the S/N ratio. They would not, I tried swapping TiVO boxes and it did not work
However, Good news! I went on line and purchased 3 - 12 dB pads. and placed them at the splitter on each of the lines that entered my house (at DC they are a short).
This dropped my S/N down to 32dB and fixed my pixelation.
There is something strange about how TiVo keeps telling people to reduce SNR. There is no such thing as too high SNR -- it is the ratio of signal to noise. In some cases the problem could be too much (i.e., a "hot") signal, which can cause video dropouts or pixellation because of tuner overload. However the cure is really just reducing (attenuating) the signal and the reduction in SNR is just incidental to that.
If your signal is in the 80-99 range recommended by Tivo and your SNR is 32 dB or higher (including 37 dB or more) you should be getting good video. Specifying an upper limit of SNR when the signal strength is in the recommended range (which TiVo does) makes no technical sense .......... UNLESS the value reported as SNR by TiVo's isn't actually SNR. (??)