AVS Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter · #1 ·
Hopefully I can explain the problem well enough... also hoping it's something simple I'm missing because it's a bit frustrating as of right now.


So, I've had no problems receiving OTA channels for the past 2-3 years on my 32" inch LG. It was a simple coax cable plugging into the back of my HDTV, search the channels, yadda yadda. 32-1, 2-1, 5-1, etc. those have all worked fine for me for years.


Now as of last week, I received a letter from Comcast stating that I have to get their Digital Box as they are converting all of their signals to digital. No biggie, free of cost, get On Demand now... okay.


After setting it up today, I began to wonder how I would receive my OTA channels going forward. Before I would just do 2-1 or whatever to get CBS (Channel 2)'s HD signal.


Now that I'm bogged down by this Comcast digital box, all the channels and the cable go through the box. Okay. So I switched to CBS, and then found the CBS-HD channel in Comcast's listings.


Now when I get to the CBS-D channel, I can hear audio, but I get no video. What gives? How can I continue receiving and getting to my OTA HD channels with this new Comcast Digital Box.


Also, I don't plan on getting the HD package from Comcast, I was more than happy getting the 10-11 OTA HD channels I was getting for free (CBS, NBC, Fox, PBS, etc.)


Hoping this is a simple problem... please let me know if you need any clarification or if I didn't explain properly. I await your help!



For some more detail, here's how it's connected. Out of the wall into the Cable In portion of the Comcast Digital Box. Coax cable runs from Cable Out to the TV. No other steps, pretty direct.
 

·
Registered
Joined
·
87 Posts
If you didn't get a HD set top box, then you need to add a splitter, and split your cable, one leg to the comcast set top box. If the set top box has a composite yel-red-wht video output, run that into one of the video inputs on the TV, and the coax from the 2nd leg of the splitter to the ANT/Cable RF input on the TV. If you just got the simple DTA box with the ch3 output, then you need to add a A/B switch before the RF input on the TV and switch between the DTA output and the direct cable input in the TV.


Your really talking about the local network stations received by the comcast cable and not an antenna, right?


If you not sure what I said, then it would help by saying what box you got from Comcast, and I'll help more.
 

·
Registered
Joined
·
87 Posts
OK, then you will add a splitter, and the output of the STB would use the yellow, red, white to the TV, and the 2nd leg of the splitter to the ANT/Cable RF in on the TV.


Switch between tuner for your network HD's, and the video input for your output of your set top box for the SD cable channels.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #5 ·
Jay, my man!


Seems simple in retrospect, but thanks for saving me the added stress of actually figuring it out. Awesome! Thanks again fellow Illinoisian.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #7 ·
Just glad there was somebody this hour to help out. I was going to sleep on it, but you know that never works out well, I'd be putzing around at 3am again hahah....
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #8 ·
A quick question in case you've dealt with people that had this problem or you yourself have.


I did all the split and everything was pretty good. OTA HD channels came in perfectly, everything on the cable split was fine.


The quality though going into my Video 1/AV 1 TV input (the Comcast box feed) via the RCA Video Output was awful though. really stuttered, really pixelated. I could barely watch basketball. The most telling example was the ESPN Bottom Line which would stuttered all the way through its scroll.


Thinking that it was possibly the splitting that was causing this, I removed the split and did my cable directly IN the Comcast box, then fed the signal via the RCA/Composite out.


Same terrible quality. Same stuttering, etc.


Next step, maybe it was faulty cables. Luckily I had 3 RCA cables hanging around, one brand new, another I was using for a DVD player in another room. Tried all three, nearly identical picture quality.


Shouldn't my RCA/Composite be giving me nearly the same, if not better picture than the coax? My Comcast digital cable is nearly unwatchable via RCA output. So if I still want to receive my OTA HD, and still hook up this box, I'm going to have to switch cables every single time?
 

·
Registered
Joined
·
87 Posts
Interesting issue with your composite cables. They should certanly give a good solid picture with composite out, and the set top box is a new model.


Next, you might want to swap the set top box at the local Comcast office and hope they have a newer model to give you.
 

·
Registered
Joined
·
109 Posts
Check your signal strength on the Motorola box. If you have the silver on demand/dvr remote, simply power off the cable box and press the OK button within two seconds. Option 2 in the menu is OOB Status. Here you will find the SNR (which should at least be FAIR not POOR,) if you have a carrier lock, and if it is in hunt mode. Exit by pressing power twice. Test on your worst channel first, then better ones. It may be better to continue this in the non-HD cable forum if you could post results there.
 

·
Registered
Joined
·
1,493 Posts

Quote:
Originally Posted by FedEx227 /forum/post/18232483


.......Shouldn't my RCA/Composite be giving me nearly the same, if not better picture than the coax? My Comcast digital cable is nearly unwatchable via RCA output. So if I still want to receive my OTA HD, and still hook up this box, I'm going to have to switch cables every single time?

It sounds like your signal strength at the wall may be borderline. Do you know if other splitters exist between your cable drop and your connection point at the wall? Are you saying that the only output of the cable stb that provides non-stuttering video is the coax (rf) output?


The motorola stb may have a less sensitive receiver than the QAM tuner in your hdtv and the marginal signal strength is enough for reception on the hdtv only. It is Comcasts responsibility to provide you with adequate signal strength for consistent operation of your stb. I suggest you call them and insist on keeping your external splitter in the path.


BTW, your hdtv has a QAM tuner for reception of cable company clear QAM channels. These should not be confused with OTA reception, which requires an antenna.
 

·
Registered
Joined
·
20 Posts
Discussion Starter · #12 ·

Quote:
Originally Posted by raouliii /forum/post/18237672


It sounds like your signal strength at the wall may be borderline. Do you know if other splitters exist between your cable drop and your connection point at the wall? Are you saying that the only output of the cable stb that provides non-stuttering video is the coax (rf) output?

I haven't been around in a bit, but I thank you guys for the help!


To answer your last question, yes. here's a quick overview how it broke down.

Option 1

Cable out of the wall -> Coax In to STB -> Coax Out of STB into TV


This option provides me the best picture through my Comcast STB but unfortunately does not allow me to get my QAM channels (thank you for the clarification).

Option 2

Cable out of the wall -> into Splitter -> one split directly into TV's Coax input -> one split into Comcast stb -> Out of STB into TV's AV input (via RWY/Composite cable)


The positive with this option is I'm able to watch my QAM channels thanks to the direct split into the TV. However, anything watched on the AV input through the STB is pretty poor, especially with movement. The most glaring example is ESPN, their lower third scroll "BottomLine" is extremely stuttered and with this option sports are practically unwatchable due to the stuttering on really any motion.


So I'm kind of stuck here... I did the diagnostic and it graded out pretty well. "20 db - Good". So I don't know really...


Could it possibly be a poor splitter, or poor composite cables... or is it just a matter of me trying to split a picture too many times?
 

·
Registered
Joined
·
296 Posts
I've been looking for the non-HD forum to post this, but can't find it. So if this needs to be moved, just tell me where. I am aware I"m reviving an old thread, but this is the closest I could find to my situation.

I have split the Comcast cable, with one split going to a TiVO HD, and the other into a Motorola DCH70 Digital Box (not HD) so that I can get some On Demand content (you cannot access OnDemand with a TiVO, and, I know, it will not be in HD). The box has worked previously on a split cable in another room, but here, it is not picking up several channels. I have tried a new 2.05 GHz splitter, and while it helped the TiVO's signal in a small amount, the DCH70 is still missing several channels (it reads something to the effect of "This channel will be available shortly." It's not a big deal, but could this be a signal problem JUST on this one cable connection, as I do not have this problem when the DCH 70 was hooked up to a different connection on a splitter?
 

·
Registered
Joined
·
921 Posts

Quote:
Originally Posted by hybucket /forum/post/21175146


"This channel will be available shortly."

My Motorola box on Charter did that when the signal level was a little too low; most channels worked, a few didn't.


In MY case, Charter had to replace the outdoor (demarc) splitter mess with a unity gain amplifier.
 

·
Registered
LG 55" C9 OLED, Yamaha RX-A660, Monoprice 5.1.2 Speakers, WMC HTPC, TiVo Bolt, X1
Joined
·
45,727 Posts

Quote:
Originally Posted by hybucket /forum/post/21175146


I've been looking for the non-HD forum to post this, but can't find it. So if this needs to be moved, just tell me where. I am aware I"m reviving an old thread, but this is the closest I could find to my situation.

I have split the Comcast cable, with one split going to a TiVO HD, and the other into a Motorola DCH70 Digital Box (not HD) so that I can get some On Demand content (you cannot access OnDemand with a TiVO, and, I know, it will not be in HD). The box has worked previously on a split cable in another room, but here, it is not picking up several channels. I have tried a new 2.05 GHz splitter, and while it helped the TiVO's signal in a small amount, the DCH70 is still missing several channels (it reads something to the effect of "This channel will be available shortly." It's not a big deal, but could this be a signal problem JUST on this one cable connection, as I do not have this problem when the DCH 70 was hooked up to a different connection on a splitter?

Probably a signal integrity or strength issue. If things still work fine in the other room, then you need to track down what is happening between the main entrance into the residence and the location where the problem is. Start by looking at the terminations; be sure they all look solid and the connectors are screwed in firmly. As a test, remove any splitters not needed between the two points. After that, it's a matter of looking at the individual terminations.
 

·
Registered
Joined
·
296 Posts
Thanks - did more investigating, and turns out ALL the outlets for cable are doing the same thing, not just the one I first thought, so it's obviously a signal problem. I'll try an amp at the point where the cable comes into the unit - at that point, it is split three times, and then another two at the main outlet. If the amp doesn't help get the signal on my TiVO up to a more acceptable level (channels are running anywhere between 60-90 percent, only a couple pixilating), I guess I'll have to bite the bullet and call Comcast. Ugh!
 
1 - 17 of 17 Posts
Top