AHHH HDTV isn't so HD!!

[guess88]

So, this has been sucking. I just recently got a new CRT big screen.. Mitsubishi Diamond 65813, and since it's HD ready, we figured we'd go digital cable with HD as well. Anyway, the TV looks great with DVD's so far, and it actually looks pretty good with the internal HD tuner (all like 7 channels it shows), but after finally getting the external comcast HD box working, i found that the picture looks like crap with it. I was thinking it might be a coax cable problem, but i swapped cables with the one going to the internal HD tuner and the internal one still looked pretty sharp. Not great, but MUCH better than the picture coming out of the external HD box. Anybody got any ideas? Is it signal quality? EMI? Ghosts?? Boogie Man?? Any help appreciated. Thanks much.. this site's already been invaluable to me.

 

[mfabien]

You didn't say what STB you have. If the cable provider can tell you how to access diagnostic pages, you could then see the signal strength. Proper signal should be between -10 db and + 10 db (0 db being perfect). If the cable length is reasonable and there is no splitter, the cable problem could be the quality of the cable from the telephone pole.

Your cable signal should provide as good an HD signal as anything else. Get the provider's tech to see the difference with your OTA and they ought to work at fixing the signal problem.

I am assuming here you have setup your STB properly for Picture aspect (16:9 vs 4:3) and Picture Format (480i, 480p, 720p, 1080i). If not, that could be your problem.

 

[BMXTRIX]

You also haven't said how you have hooked your cable box to your TV or what specific channel you are watching.

You must be using component or DVI/HDMI connections to see the HD channels correctly
You must also actually be on an HD channel, not just have an HD box. Try INHD which is likely in the 300 or 500 channel range. For me it is channel 712 or so for my 24/7 INHD channels.

It is also likely that your Mitsubishi only accepts 1080i input and does not offer full ATSC compliant HD inputs. So, you should work with native 1080i sources.

 

[guess88]

As for now, the HD box is connected with component video cables.. from the box straigh to the back of the tv. I ordered a DVI cable, but that won't be in till later this week. The tv is setup properly in terms of 1080i, and 480p. The box has an upscaler to convert 480i to 480p. I've tried it both ways, about the same results really. The problem is the picture's are very snowy. I don't have a bad picture in terms of shape or color, but just horrible snowy picture. It's worse than when I had it hooked up analog. The odd thing is that some of the HD channels actually come out looking great.. much much clearer. While not at their ability, they blow away the other channels. But even my basic channels look horrible. And that's not right. Cable technician's coming friday to check it out. I'm leaning towards poor signal. We had a similar issue with our cable modem, and had to run a new dedicated wire just for the modem. The coax cable we're using is real cheap too though, and it's being run long distances. Depending on the diagnosis of cable tech guy, i might consider rewiring most of the house and going Belden 1694a.

Also, i'm looking at signal amplifiers. The Belden cable's sweep tested to 3ghz, and i see a lot of splitters go up to 2.5ghz. Anyone know what bandwith range digital cable runs? If I end up having to rewire the house, I want to do it all right and setup for future upgrades. Also, can anyone recommend a 2-3 way splitter, and also an amplifier/splitter as well? Thanks much.

 

[guess88]

Also.. sorry.. forgot to mention. the external digital cable and HD box is a Motorola unit provided by Comcast.

 

[mfabien]

If one day you consider the possibility to ask Comcast to supply the Motorola 6412 STB/DVR (dual tuner), you should use a "two way" amp/splitter. Otherwise, you will lose interactivity because of the lost of your IP address.

 

[BMXTRIX]

Definitely a cable issue. The Motorola boxes, as far as I have seen, are far superior to the Scientific Atlanta boxes. The guys from Comcast should also come out to measure signal levels and everything else.

We had a similar issue, where things were going great, then one day our Internet connection started getting flakey and the digital channels started going out.

Turns out we (for no apparent reason) started getting to STRONG of a signal at our home and they had to cut back the signal some. Worked perfect after that, though it was a hassle to get it taken care of, they did take care of it at no additional charge to me.

 

[djoxygen]

The problem is the picture's are very snowy. I don't have a bad picture in terms of shape or color, but just horrible snowy picture. It's worse than when I had it hooked up analog. The odd thing is that some of the HD channels actually come out looking great.. much much clearer.

Definitely points to cable issue. Snow pretty much happens before the signal gets to the tuner/decoder. It would be very difficult to induce snow into the RGB/DVI/HDMI lines once the channel is tuned in. You'd have to run the wires through your vacuum cleaner motor or something similarly absurd.

 

[DSMCasey]

I had the same problem with my digital cable. I have Cebridge Cable, and I live in a brand new development. They had already laid the underground cable coax when my house was finished, however when they built my neighbors house they cut the underground coax (if you haven't seen an underground coax they are REALLY thick). After getting NO SIGNAL the cable company came out and ran "temporary cable" to my house from a block away. The signal was TERRIBLE. When it rained I lost all TV and when I did have a signal it was snowy and looked like crap. My cable modem would also go out when it rained. I cancelled my cable after making NUMEROUS attempts to get them to get it fixed. I got Dish Network and besides the dorky looking dish on my house I love it. It has a better picture than any cable I have ever seen (although good digital cable should be comperable). I just wish I could get the cable company to get rid of all the "temporary cable" running through all the yards in my neighborhood. It looks like crap but everyone in the neighborhood has called them a 100 times and they just ignore us. Don't get Cebridge cable if you ever have the pleasure of being in thier area.

-Casey

 

[guess88]

Thanks for tips guys.

Yeah, we have Comcast here, and so far, in my local area at least, they've been pretty cool. So, the tech guy came, and didn't really do anything. I described to him the situation, and basically he pointed out that, since the older analog channels are running through the digital box, the box tries to convert it, and doesn't do a very good job, so it's best to bypass the box for those channels. Coincidentially, I already had that wired for PIP purposes, and sure enough, it actually came to be true. All the analog channels look pretty good without the box, and when i switch to the digital channels using the box, the picture quality's pretty great.. especially the HD. I still got a motorla signal amplifier, and monster HD 3 way splitter to upgrade the line anyway though. Not installed yet, but we're redoing the whole room soon, and i'm flush mounting a cable junction box inside the wall. Might rerun the whole house with some Belden 1694a just for the sake of it too.

My only gripe right now is that the motorla dtv tuner.. a 6200 model i believe, does NOT output dolby digital, and it's KILLING ME. I know everything's connected properly, and i'm assuming it's a firmware update they need to do or something. I love the picture quality, but just knowing i have to listen to pro logic II, when i KNOW DD 5.1 should be accessible hurts. I've seen on some other boards that other people had this problem too. I talled to the comcast tech and it's the first he's heard of it. The people on the boards still haven't found a solution either.

Help?

Anyways, thanks for the tips guys. Audioholic's been great to me

 

[DSMCasey]

You can only get 5.1 on HD channels, not regular channels...I have a problem with my old Kenwood receiver sometimes it won't switch over to 5.1 when I put it on a HD channel, I usually turn the receiver off and change the channel to SD TV then back to the HD channel and that does the trick. I've read somewhere else that some people have that problem. Also, I don't think all HD broadcasts have 5.1 sound.


-Casey

 

[MDS]

The various channels on cable vary in whether or not they broadcast DD 5.1, DD 2.0, PCM, or strictly analog.

I don't have HD, just digital cable (Time Warner) and have no problems with the receiver locking on to DD 5.1 and decoding it properly. If you can't get DD 5.1 reliably when the channel is definitely broadcasting in that format, you either have a problem with the cable box or the receiver.

Good luck getting a resolution from Comcast. I dealt with them in FL when I visited my family, and couldn't find one single installer or get a tech person on the phone that knew anything at all about 'digital' formats. It's hard to believe Comcast is the largest cable operator in the US when their tech people know less than my non-techie parents.

 

[guess88]

yeah.. I'm aware not all programs are in DD 5.1 format, but programs that i KNOW should be in it, ie. superbowl, Leno, couple other programs... they all stay in pro logic II mode. I'm pretty sure it's the box.. probably a much needed firmware update. I wonder if i can get my buddy to hack into it? How do you even approach that?

 

[DSMCasey]

Are you SURE that comcast is re-broadcasting your local channels in HD? With dish network none of my local channels are re-broadcast in HD (superbowl is SD, everything on CBS, NBC, etc.), and the only way to get HD on the local channels for me is with an antenna. And like I said with dish network I've never gotten 5.1 sound except on HD channels. Not saying its not there, but I haven't seen it yet.

-Casey

 

[guess88]

I'm pretty sure it's HD. The tv switches over to 1080i resolution, and there's clearly a visual difference in picture on the HD channels.

 

[MBauer]

Comcast does HD Broadcasts

I am a Comcast subscriber who has their Digital/HD package with the Moto DVR mine will pass 5.1 I think the STB is a 6208? I use an optical cable from the SPDIF output to my receiver to get the DD 5.1

So when DD is being broadcast I get it

 

[guess88]

mbauer...

i'll check it out, but i think i have the same STB as you. I'm using the audio coaxial out, but i did have it with the optical connection before hand, and had the same results. I'll try using an optical cable again, but that really shouldn't matter. The receiver is showing a digital signal coming it, just nothing in DD 5.1. The receiver's a Denon avr-1803. You don't have any audio options that are selectable do you? The only options i can access to change are video display configurations.

 

[MBauer]

mbauer...

i'll check it out, but i think i have the same STB as you. I'm using the audio coaxial out, but i did have it with the optical connection before hand, and had the same results. I'll try using an optical cable again, but that really shouldn't matter. The receiver is showing a digital signal coming it, just nothing in DD 5.1. The receiver's a Denon avr-1803. You don't have any audio options that are selectable do you? The only options i can access to change are video display configurations.

Guess - I have a Denon 3805 and I just set mine to auto detect, so to answer your question mine is selectable as far as the audio goes.

You are correct, it shouldn't make any difference between a coax or toslink (optical) they both pass a digital bitstream. I am not familiar with the 1803. What happens with other source material, does your receiver pick up dd automatically. For example when you start a DVD it is often not 5.1 in the intro scenes but switches to DD when you get to the movie. Does your receiver switch automatically?

 

[guess88]

yeah it's fully automatic.. so it would pick it up right away. It's gotta be the STB....haven't checked to see what exact model it is yet, but i know it's a 6200 series.

 

[MBauer]

Moto Manual

yeah it's fully automatic.. so it would pick it up right away. It's gotta be the STB....haven't checked to see what exact model it is yet, but i know it's a 6200 series.

You can get the STB Manual from the Motorola site if you are interested but I think you should be able to just go to a lcoal Comcast office and exchange it? I have done that in the past with things (Cable Modems and STB's) and it has been pretty easy. It only takes a couple of minutes forthem to get a new one and record the new serial numbers. Good luck, let us know how it turns out

Mike