Coax Cable?

Discussion in 'Archived Threads 2001-2004' started by Frank Chang, Dec 11, 2001.

  1. Frank Chang

    Frank Chang Agent

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    I'm new in the digital domain. Does it matter what type of coax cable is used for digital connection between DVD and AV receiver? I've never used the coax connectors before.

    I'm connecting DVD from home theater to a family room HT. Just installed Denon 3802 in family room and did not realize 5.1 etc effects need to be sent thru digital cable. I do have spare coax run between two rooms, some for initial cable signal no longer in use and also a spare monster quad sheilded coax for satellite signal distribution. Would either of these be appropriate?
     
  2. Willem Vos

    Willem Vos Stunt Coordinator

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    Well as long as they're 75 Ohms, they should be good.

    Also, the more shielded the better, and the shorter the cable run the better (but not too short :)).

    Just put some RCA plugs on either side and you should be good to go.
     
  3. Frank Chang

    Frank Chang Agent

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    Thanks,

    The run is about 20 feet (between two rooms on different floors) and how do you know for sure if it is 75 ohms?
     
  4. Vin

    Vin Supporting Actor

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  5. Frank Chang

    Frank Chang Agent

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    Thanks, I'll give it a try tonight. I have the RCA F connectors on hand.

    Is there any theoretical length limitation for coax to conduct the digital data?
     
  6. broderp

    broderp Auditioning

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    I have been working onthis myself, in an effort to prove you can get a HIGH DEF signal thru coax, and have just as good a picture as those overly expensive MONSTER CABLES every one pushes.

    RG-59 or RG-6 is specified as 75 ohm cable.

    High Definition signal require a bandwith of about 1.5GHZ. RG-6 is good for up to 2.2GHZ. I would suggest you use RG6 as your cable of choice. I would also suggest you use Beldon cable 1694A or equivielnt for the best possible signal trasnfer with the least attenuation.

    AT 50MHz, a 100 ft section of this cable will have an attenuation of 1.7dB. Your needing less so your attenuation will be consideably less. (it is perportional, a 50ft section would only have .85dB loss etc..)

    I'd use a COMPRESSION fitting for the f-connector, like most cable company's use. And then of course the f to RCA adapters.

    Chroma delay and low frequency loss should be negligible on a run as little as 20 ft. Any slight deviations in these can be compensated for via picture adjustments and calibration.

    RB
     
  7. Bob McElfresh

    Bob McElfresh Producer

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    broderp: welcome to HTF!
    From your post it looks like you are into cable-making or at least paying attention to the numbers. I'm looking forward to your contribution.
    Keep in mind that Frank is talking about a Digital connection for DD Audio. Things like Chroma delay tends not to be an issue for audio. [​IMG]
    PS: You mention "low-frequency loss" for the coax. Could you elaborate? Most of the Canare/Belden specs I have read deal with high-frequency rolloff. Since I tend to recommend generic RG6/59 as good "starter" cable for subwoofers, low-frequency loss could be a concern.
    Frank: use that "other" cable and you will be fine. Leave the Monster stuff for DSS since it should be RG6.
     
  8. Frank Chang

    Frank Chang Agent

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    Thanks everyone!

    Bob, you think I should use the "other" cable. It's 5 or 6 years older than the monster, solid conductor copper with I believe foil sheilding originally run to conduct cable TV signal. I don't know how to tell if it is RG-6 or RG-59 as there are no markings and I am obviously a cable neophyte. I did not understand why you suggested not to use the quad sheilded green monster satellite cable instead since both are available. Looks like the run is probably closer to 30 feet long.
     
  9. RAF

    RAF Lead Actor

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    Lots of great information here:
    http://www.bus.ucf.edu/cwhite/theater/DIYCable.htm
    (Sometimes the link is down so keep trying if you don't get through.)
    Chris White has done a lot of research on this and his DIY solution (using Canare products) is defintely cost effective if you have lots of cables to run.
    Good luck.
     
  10. Frank Chang

    Frank Chang Agent

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    Robert,

    Thank you very much, very informative and well done. I'll be ordering some parts and making some long run video, sub-woofer, and digital coax cables soon, and component in the future!

    How about S-video cables, any similar web site? I've been using radio shack S-cable and their best s-connector with pretty good success, for longer custom runs primarily connecting from receivers to monitors.

    I don't want to start a huge cable controversey here but I was wondering about the quality level for the audio inteconnects. Good enough for HT interconnects? Good value for long runs? Can't imagine I should replace high end audiophile interconnects in my dedicated stereo system?

    Probably no true answer as sound quality is relative and so subjective, just trying to get a feel for how they sound.
     

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