certain channels not clear?
tvnutt
Newbie

Hi,

So far my family loves FiOS. So many more channels than our old provider. However, some channels don't seem to come in clear. They're not pixelated, however during a shot change(camera changes from one view to another) in a tv show or commerical I see little blocks in the image that blend in with the scene. Sometimes the areas around the people's faces seem grainy. Is it possible that some channels are being compressed BEFORE they're sent to Verizon? I notice this on channels: Nuvo TV, MTV2, BYU and Fox sports.

Here's our setup:

We do have an HD TV(Sony Bravia 52 inch) with HDMI cords. Our coax(brand new) and HDMI are gold plated. The STB is set at 480p(tried the SD override feature and the picture quality was the same but the "channel guide" looked soft). The tv is set to 1080i. We had some hottness because the SNR in-band status was 37-38. We attached two 6dB attenuators to lower it down to about 36.5.

anyone else experiecing something similar?

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Re: certain channels not clear?
retiredme
Specialist - Level 1

I am a little unclear about your post, but if I understand it you have a 1080 TV but your STB is outputting 480p. That is likely the cause of the pixellation as your TV tries to rescale the information. Try setting the STB override to "off", and the STB output to 1080, and the TV type to 16:9. I don't know what you mean by signal strength and the word "hotness", but most people do not need to use attenuators. Some model numbers would be helpful for further discussion.

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Re: certain channels not clear?
Keyboards
Master - Level 3

@tvnutt wrote:

Hi,

We had some hottness because the SNR in-band status was 37-38. We attached two 6dB attenuators to lower it down to about 36.5.



You have made the same mistake that most people do in assuming SNR is the same as sigmal strength.  IT IS NOT!!!!

SNR (signal to noise ratio) is just that, a ratio of the signal strength to the background noise (it is a quality of signal unitless measure not strength).  Signal can be "hot" or low and still give SNR numbers like you post.  If it was signal strength you measured then adding 2 6 dB attenuators would have lowered the number by 12 dB to 25 - 26, but it didn't because the ratio barely changed (probably at 37-38 the limit of the STB measuring capability).  The net result of lowering the SNR as you did was to marginally degrade the quality of your signal.

The reality is that the higher the SNR the better.  An infinite SNR would be the best one could hope for.  Signal strength is measuerd in dBm or dB uV not plain dB.

Sorry, the engineer in me just hates to see misinformation or misunderstandings like this.  I now take my technical hat off and breath again Smiley Frustrated

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