Hi Def with Coax Cable???

Discussion in 'Playback Devices' started by Chris Tedesco, Aug 21, 2005.

  1. Chris Tedesco

    Chris Tedesco Second Unit

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    I am pretty sure that you cannot get a true High Def picture using a Coax, but I just got done installing a Samsung 23 inch LCD and I can't seem to see the difference.

    My Dad had Comcast come out and install the HD Box, and they connected it using a Coax. Well, I told my dad that you can only recieve a true HD picture with Components or DVD(or HDMI). He disagreed, and we argued. [​IMG]

    So went out and bought a component and set it up through the TV menu. I am at this point baffled because I can't see a noticable difference. What am I missing here, am I wrong???
     
  2. Robert_J

    Robert_J Lead Actor

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    The RF (coax) connection between the cable box and the TV is the lowest quality connection you can use. You should have seen an improvement going to component cables. What are you doing wrong? Don't know. You haven't given us much information to go on. What model TV? What model cable box? What show did you use to demo HD? Was the show actually HD or just SD being broadcast on the digital channel?

    -Robert
     
  3. Chris Tedesco

    Chris Tedesco Second Unit

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    I don't have the model number on the TV, but it's an LCD 23 inch Samsung. Comcast DVR cable box. I was showing HBOHD (spiderman 2). Showing INHD channel. Discovery HD.

    I guess my question is, even though coax is of lower quality, can you still get an HD picture from it in it's correct aspect ratio? My assumption was no, but after watching and comparing I think my assumption was wrong.

    I did show Standard definition as well, and it actually looked worse on the component cable.

    Sorry I can't provide the model number though...
     
  4. Rocky F

    Rocky F Second Unit

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    I know a guy who had a similar situation recently. Actually his was a little worse. The cable installer had hooked his system up with both cable and component, but he had mixed up the red video cable and the red audio cable, so the picture through component didn't have any red, so he was just watching it through coax because component looked so bad. I fixed that problem for him, but I could also tell that he still wasn't getting HD through the components. I then figured out that the box was not set up properly. It was only outputing 480i through the components. I bet you are having the same issue. I can't know for sure if you have the same box as he did, but it's possible so try this: turn the cable box off, then hit the menu button on the remote. In the display on the box 16:9 should appear. Pressing the up and down buttons should allow you to scroll through various set up options. If you see 480i, you can change it to 1080i. I don't have the box or remote myself to I can't tell you exactly which buttons to push. but I remember this being fairly easy. Just remember that you are going to be looking at the small display on the cable box, not the tv itself.

    Hope this helps
     
  5. John S

    John S Producer

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    You can get real HD over cable....

    You cannot route it through a Standard DVR though, has to be an HD DVR.

    So many things need to be checked and hooked up right to get it though.....

    It's getting iffy on component video and cable HD though...

    Do you have DVI/HDMI available?


    On component video make sure you have the cable box setup to display HD at 720p for your display.
     
  6. Mike Wilk

    Mike Wilk Stunt Coordinator

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    If you are on Comcast in Maryland, then I'd guess you have a Motorola cable box. If so, the model number should be on a label on the bottom of the box. I have a 6204, single tuner DVR, that has a coax out (which is limited 480i) and component (Red, Green, Blue) for HD (720p or 1080i). I believe this box will also do DVI if the local cableco has enabled that connection. You can determine what a Moto box is sending by turning on the TV but leave the box off; press Menu on the remote, this will cause the internal menu to appear. From here, you tell the box what send over which connection. When finished, press power to turn off and power again for normal operation of the box. Report back and I or someone else can give you more help.

    When I am only watching an analog (lower tier below 100) channel I get a direct coax feed from the wall before the cableco box. I ran a 5-1000MHz, -3.5, 2-way slipper to feed the set directly and to feed the box for digital/HD.

    BTW, if you have a Samsung 16:9, it might be the LNR 238W. I just got one for under $900 at Costco. Again, there should be an identifing sticker; on the back this time.

    BTW 2, you can get a 16:9 image over the coax connection but it won't be HD.

    Generally speaking, a TV will NOT let you change the zoom stretch of a picture if it is receiving an HD signal. A SD signal, even over component, can be stretched or zoomed.

    YMMV
     
  7. Chris Tedesco

    Chris Tedesco Second Unit

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    Yes, that's the TV model LNR 238W. The interesting thing here is getting to the menu on the Comcast Digital Box. Why they have you entering the menu that way is baffling. I will try that tonight. It's got to be set at 480i currently, that would be the only explanation.

    So John, you're saying it's possible to get an HD connection/reception through Coax? I'm not hearing that from the others. I'm still a bit confused about that.
     
  8. Kerry.J

    Kerry.J Auditioning

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    Chris, John is absolutely right; true/real HD signals can be transported/distributed over coax. Coax is how the cable company gets the signal to your house in the first place or how a satellite company distributes the signals though out the home.

    It could be a variety of issues such as: the I/Os, content provided (HD or SD), or the resolution settings of the STB (set-top-box), DVR, TV or DVD player.

    There are many factors involved and none have to do with the coax.
     
  9. Kwang Suh

    Kwang Suh Supporting Actor

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    Of course coax can carry HD.

    However, I think you're confused as to how the connections actually all work together.

    It should be something like:

    Wall: coax -> Cable box: coax -> Cable box: component/DVI/HDMI -> TV: component/DVI/HDMI.

    So, as you can see, the only time coax is used is from the wall to the cable box. Using coax from the cable box to the TV means that you will NOT have HDTV. That connection has to be component/DVI/HDMI.
     
  10. Chris Tedesco

    Chris Tedesco Second Unit

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    That's what I mean. I know that the cable company carries the signal to the box, but I'm was talking about the Cable Box to the TV. That connection. What happens when you use a coax from the box to the TV? Can that still display HD?

    This is all good information, thanks everyone!
     
  11. Robert_J

    Robert_J Lead Actor

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    Coax between the cable box and the TV is an analog RF connection. At best, it will carry a 480i signal. You need component, DVI or HDMI cable between the cable box and the TV to HD>

    -Robert
     
  12. Jeff Gatie

    Jeff Gatie Lead Actor

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    If the coax is a pass-thru from the box (i.e. it is not tuned by the box), you can get HD from the cable only if you have a cable compatible HD tuner in the TV. This is probably not the case. It looks like you are getting a HD signal that is down mixed to 480i.
     
  13. Chris Tedesco

    Chris Tedesco Second Unit

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    Well, I went to the Comcast DVR Box's menu and guess what? Bam! It was 480i!! So I changed it to 1080i and all is well! But as all things, Dad still thinks the analog looks crappy, ah well, did my part!

    Thanks Guys!
     
  14. Dan Driscoll

    Dan Driscoll Supporting Actor

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    The analog channels (
     

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