NBCHD &CBSHD - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 11 Old 08-06-2012, 06:07 PM - Thread Starter
Newbie
 
Hannous's Avatar
 
Join Date: Aug 2012
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Ok, so this is somewhat bizarre, but i am having issues with my NBCHD & CBSHD feed.
I'm running Comcast cable through coax line into a splitter that feeds into the HD set top box and cable modem.
HDMI connection into Samsung plasma 51pnd7000 from set top box.

I am getting regular pixelation on both NBCHD & CBSHD ONLY. Anyone know what can cause this? Every other HD channel, including all HBO/Show/ESPN etc. come in fine even when the two are pixelated. As are Fox and ABC.

If I jiggle the coax wires they go back to normal for a brief period of time, but then something makes it pixelate again. Only those two channels. I've tried multiple coax cables in different configurations, moved power cords around to try and minimize interference (it's a jumbled mess behind theree) but the problem persists. Is it my splitter? My set top box? Cables? Configuration? This doesn't happen in the other room on that tv. Will an amplifier help?
Hannous is offline  
Sponsored Links
Advertisement
 
post #2 of 11 Old 08-06-2012, 07:37 PM
AVS Special Member
 
gremmy's Avatar
 
Join Date: Sep 2003
Location: St. Louis, MO
Posts: 3,942
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Quote:
Originally Posted by Hannous View Post

Ok, so this is somewhat bizarre, but i am having issues with my NBCHD & CBSHD feed.
I'm running Comcast cable through coax line into a splitter that feeds into the HD set top box and cable modem.
HDMI connection into Samsung plasma 51pnd7000 from set top box.
I am getting regular pixelation on both NBCHD & CBSHD ONLY. Anyone know what can cause this? Every other HD channel, including all HBO/Show/ESPN etc. come in fine even when the two are pixelated. As are Fox and ABC.
If I jiggle the coax wires they go back to normal for a brief period of time, but then something makes it pixelate again. Only those two channels. I've tried multiple coax cables in different configurations, moved power cords around to try and minimize interference (it's a jumbled mess behind theree) but the problem persists. Is it my splitter? My set top box? Cables? Configuration? This doesn't happen in the other room on that tv. Will an amplifier help?

My experience is with OTA and not cable, but I'm guessing that the same principles apply. I'm guessing, then that the signals for NBC and CBS are lower than the rest of your channels, and it sounds like they keep dropping below your set top box's signal threshold. You could try adding a distribution amplifier as near the source as possible (prior to any splitters, etc.) and see if that helps.
gremmy is offline  
post #3 of 11 Old 08-06-2012, 08:11 PM - Thread Starter
Newbie
 
Hannous's Avatar
 
Join Date: Aug 2012
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks. Would that explain why sometimes the picture is ok, but sound cuts off? Again, only those two channels.
Also, is there a difference between a distribution amp before the splitter and an amp with a splitter included?
Hannous is offline  
post #4 of 11 Old 08-06-2012, 10:01 PM
AVS Special Member
 
gremmy's Avatar
 
Join Date: Sep 2003
Location: St. Louis, MO
Posts: 3,942
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Quote:
Originally Posted by Hannous View Post

Thanks. Would that explain why sometimes the picture is ok, but sound cuts off? Again, only those two channels.
Also, is there a difference between a distribution amp before the splitter and an amp with a splitter included?

First question: Did you split the signal or did your cable company? If the latter, I'd have them fix this. You seem to be having dropouts on channels that you're paying for. They have the right equipment and the knowledge to take the guess work out of it (at least, one would hope).

Per your questions:

Yes, low signal could cause both audio and video dropouts.

You could use an active splitter (where the amp is in the splitter) or you could use a distribution amplifier further up the line. The benefit of using a separate amp is that you could put it closer to the source, where the signal is strongest. This is because an amp cannot create signal that does not exist.. it can only boost existing signal high enough to compensate for losses further down the line caused by long cable runs, splits, etc.

Another benefit of a separate amp is that you could get one with variable gain and then find the proper amount of gain via trial and error.
gremmy is offline  
post #5 of 11 Old 08-07-2012, 04:21 AM
AVS Addicted Member
 
Ratman's Avatar
 
Join Date: May 2002
Location: Collingswood, N.J.
Posts: 14,398
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 138 Post(s)
Liked: 273
Try (temporarily) eliminating the splitter and run the feed directly to the cable box. That will give you an additional 3.5 dB of signal. If the problem stops, call cableco to adjust levels.
You can use one of these to connect the two coax cables if necessary:
http://www.radioshack.com/product/index.jsp?productId=2103459
Ratman is offline  
post #6 of 11 Old 08-07-2012, 04:47 AM - Thread Starter
Newbie
 
Hannous's Avatar
 
Join Date: Aug 2012
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks all. One possibly key piece of info I've left out is that I live in an apartment building. Not sure if that matters at all.
Hannous is offline  
post #7 of 11 Old 08-07-2012, 03:03 PM
AVS Special Member
 
ClearToLand's Avatar
 
Join Date: Jul 2001
Location: Central NJ, USA
Posts: 1,734
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 17
SUBTITLE: Logical Troubleshooting...
.
Swap the TVs:
.
  • If the problem follows the TV, it could have a tuner problem.
    .
  • If the problem remains in the room, one-by-one swap each 'item' between the TV and the pole for both TVs. When the problem moves, you found the culprit - replace it, or have Comcast come out and replace it.
.
Good Luck! smile.gif

Low Post Count <> Low Knowledge ergo High Post Count <> High Knowledge

ClearToLand's Picks For Best Answers to Common ReplayTV Questions

Remember, it's only TV...
ClearToLand is offline  
post #8 of 11 Old 08-07-2012, 04:05 PM
AVS Addicted Member
 
Ratman's Avatar
 
Join Date: May 2002
Location: Collingswood, N.J.
Posts: 14,398
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 138 Post(s)
Liked: 273
Logically (through reading) I didn't review anything that indicates the OP had more than 1 TV/cable box and 1 cable modem. wink.gif
Also... if using a cable box, the TV's tuner is not part of the logical equation.tongue.gif
Ratman is offline  
post #9 of 11 Old 08-07-2012, 06:14 PM - Thread Starter
Newbie
 
Hannous's Avatar
 
Join Date: Aug 2012
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Reading comprehension doesn't seem to be his strong suit.

In any event, I plugged directly into cable box circumventing splitter. Issue remains.

I'm zeroing in on the cable box as the issue. Will have Comcast swing by and see if that works. Will go to amp if that doesn't work.

Thanks,
Hannous is offline  
post #10 of 11 Old 08-07-2012, 06:49 PM
AVS Special Member
 
ClearToLand's Avatar
 
Join Date: Jul 2001
Location: Central NJ, USA
Posts: 1,734
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 17
SUBTITLE: Not Here to Step on "Local Toes"... wink.gif
.
  1. Quote:
    Originally Posted by Ratman View Post

    Logically (through reading) I didn't review anything that indicates the OP had more than 1 TV/cable box and 1 cable modem. wink.gif ...
    .
    Quote:
    Originally Posted by Hannous View Post

    Ok, so this is somewhat bizarre, but i am having issues with my NBCHD & CBSHD feed.
    I'm running Comcast cable through coax line into a splitter that feeds into the HD set top box and cable modem.
    HDMI connection into Samsung plasma 51pnd7000 from set top box.

    I am getting regular pixelation on both NBCHD & CBSHD ONLY. Anyone know what can cause this? Every other HD channel, including all HBO/Show/ESPN etc. come in fine even when the two are pixelated. As are Fox and ABC.

    If I jiggle the coax wires they go back to normal for a brief period of time, but then something makes it pixelate again. Only those two channels. I've tried multiple coax cables in different configurations, moved power cords around to try and minimize interference (it's a jumbled mess behind theree) but the problem persists. Is it my splitter? My set top box? Cables? Configuration? This doesn't happen in the other room on that tv. Will an amplifier help?
    .
    I guess one of us is misinterpreting that statement... confused.gif
    .
  2. Quote:
    Originally Posted by Ratman View Post

    ...Also... if using a cable box, the TV's tuner is not part of the logical equation.tongue.gif
    .
    Yeah, I was both thinking "Old School" *AND* trying to keep the Logical Troubleshooting Concept as simple as possible for the OP. redface.gif

    Explaining how to troubleshoot something is *SO* different depending on the "Target's" knowledge / technical ability / ability to think logically / etc... wink.gif I was just trying to explain it as "Black or White" as possible without going into "Gray" (swapping power cords).

Low Post Count <> Low Knowledge ergo High Post Count <> High Knowledge

ClearToLand's Picks For Best Answers to Common ReplayTV Questions

Remember, it's only TV...
ClearToLand is offline  
post #11 of 11 Old 08-07-2012, 06:58 PM
AVS Special Member
 
ClearToLand's Avatar
 
Join Date: Jul 2001
Location: Central NJ, USA
Posts: 1,734
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked: 17
SUBTITLE: Lost Newbie (Joined: 08/06/12) Has an Attitude - You Can Have Him - BYE!... biggrin.gif
.
Quote:
Originally Posted by Hannous View Post

Reading comprehension doesn't seem to be his strong suit...
.
Where clearly posting your equipment and conditions doesn't appear to be your's.

I replied just trying to help you out, share my knowledge, and relax a bit.

I wish you the best in finding your solution - I will now 'Bow Out'.

Good Luck! smile.gif

Low Post Count <> Low Knowledge ergo High Post Count <> High Knowledge

ClearToLand's Picks For Best Answers to Common ReplayTV Questions

Remember, it's only TV...
ClearToLand is offline  
Reply HDTV Technical

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off