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DirecTV receiver home wiring question (secondary Tvs)

Discussion in 'Playback Devices' started by Erik Waibel, Apr 25, 2003.

  1. Erik Waibel

    Erik Waibel New Member

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    First, this is my first post here (I have lurked a bit in the past and liked what I saw, so I am joining in to actively participate!). On to my question:

    I have had my two RCA DirecTV receivers for a year now and I LOVE the picture quality on my primary TVs (hooked to the receivers with s-video cables). However, my SECONDARY Tvs that are fed by coaxial cables are not super clear or sharp and appear "fuzzy". The cable I used to route to these secondary TVs from the receiver outputs was existing RG-59 from the original Time Warner cable hookup (going through a splitter too). Would replacing these runs with quad-shield RG-6 and good ends (like Thomas and Betts snap-n-seal) help to clear this up? I am concerned with the shielding of the RG-59 keeping interference out as all the runs are VERY close to live romex electrical wire (can't really avoid it due to proximity of main electrical box). I know that the receivers are capable (the s-video output looks FANTASTIC and I don't have super high-end expensive TVs by any stretch of imagination). I am aware that S-video is far superior to coax, but I don't think the difference in quality should be THIS pronounced.

    What are some experienced opinions? Worth the time and expense?
     
  2. Scott Kimball

    Scott Kimball Well-Known Member

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    There is a very noticeable difference in quality between RF output via coax and S-video output.

    How long are your RG-59 runs? Is the picture just softer, or is there RF interference (snow, wavey lines, etc...)?

    As a test, take a piece of coax and hook it up to one of the sets that gets an S-video feed, and switch between s and coax feeds (do an A/B comparison). You will notice a difference, but is it as much as on the other sets?

    If your problem on your coax setups is the introduction of RF interference, and not just a softer picture, then changing to better shielded RG-6 MIGHT be beneficial. However, if your picture is just "softer," I don't think you'll benefit from re-cabling. If you have 50 ft of RG-6, you can test the theory without running the cable... just plug it in, coiled up.

    Unless your coax is running parallel to electrical wiring at distances of less than a few inches for runs of many feet, you shouldn't have a problem with the introduction of noise from the electrical wiring.

    The other issue is the RF modulator built in to most satellite receivers is not of the best quality. They do fine pushing through six feet of cable for a local installation, but if you're pushing through 50ft of cable to house-wide distribution, they may not have the power for a good picture. You may see an improvement by feeding an outboard, tunable modulator from the A/V outs on your receiver, and modulating to the UHF band. A decent, tunable modulator will set you back at least $80... don't get the $20 modulator you can find at Radio Shack... it's the same as the one you're using already.

    -Scott
     
  3. Erik Waibel

    Erik Waibel New Member

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    Thanks Scott!

    The runs are about 30 and 40 feet each. The picture is softer, but also looks like there might be interferance as well (it seems to have a lot of "noise" in the deeper reds and oranges). I did a test last night where I took my little 13" kitchen TV and moved it next to one of the receivers where I then connected it with 6' RCA-type (composite) cables. The picture quality was OUTSTANDING compared to the long coax run . I think my friend next door has an extra 25' RG-6 cable left over from a satellite installation kit - I'll try using that as an "above the floor test".

    You mentioned possibly using a tunable modulater (a GOOD one, not RS el-cheapo) - I have no idea what some good manufacturers/suppliers are. Are there any that you can recommend? How about some online retailers that I can check out?

    Thanks for your reply!
     
  4. Robert_J

    Robert_J Well-Known Member

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    Orbitsat.com may have some Sony MRD-D1 modulators. They were made by ChannelPlus are are very similar to the 3025 model but with less channels to assign components to. I've used two of them with very good results. Parts Express has the 3025 but you will need to buy an IR target and IR emmiter (those come with the Sony) to relay your remote signals. PE also has their own Dayton line of modulators that I will be trying out soon. If they are like their other Dayton components, they will be a very good value.

    -Robert
     
  5. Scott Kimball

    Scott Kimball Well-Known Member

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    I've seen the Dayton mod on the Parts Express website. I have no firsthand experience with Dayton, but the price is attractive.

    Look at Dayton, ChannelPlus, etc. (manufacturers)
    Check out Parts Express (www.partsexpress.com) or SmartHome (www.smarthome.com).

    By all means, test it out with borrowed cable first. That might be all you need. If you do need a better modulator for the longer run, though... you should be looking probably in the $80 and up range to get the performance to push through long cable runs. Cheaper modulators are very hit or miss... sometimes a $20 mod will work great over 30ft, other times it won't. The higer-end mods have high gain RF outputs (sometimes adjustable), as well as more channel choices... and they hold the frequencies better without drift.

    -Scott
     
  6. Vin

    Vin Well-Known Member

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  7. Scott Kimball

    Scott Kimball Well-Known Member

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  8. Jerome Grate

    Jerome Grate Well-Known Member

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    This is what I did in regards with DirecTV. Each satellite receiver box location has a vcr. Instead of using the coax connection to feed the t.v. where the satellite box resides, I used the S-Video connection for the HT downstairs and the Composite connection for the bedroom t.v. I then fed the coax connections out of each VCR to the secondary t.v.s that also have vcrs. Now for each connection I did use RG-6 cable connection. If the existing Coax run is out in the open and can be changed, then I would certainly suggest changing the RG-59 cable to RG-6 Digital Coax cable. The picture was far better with the new cable, and you can still hook the secondary sets to the vcrs composite out put if one exists. My son's 20 inch Apex t.v. looks great, and t.v. in the den RCA 20 inch is just impressive. All feeding from the coax connection and then utilizing the composite connection from vcr to t.v.
     
  9. Jerome Grate

    Jerome Grate Well-Known Member

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    P.S. it was a lot cheaper.
     
  10. Vin

    Vin Well-Known Member

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    Scott,

    You're right, thanks for the correction. [​IMG]

    Vin
     
  11. Erik Waibel

    Erik Waibel New Member

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    Thanks for all of your input. Through my testing it appears that the RG-6 makes a marginal difference. I believe that the weak modulator in the RCA receiver is the culprit. I'll have to consider whether the increased clarity on my seldom-used secondary TVs is worth the cost of a better modulator.

    Decisions, decisions..........
     
  12. Vin

    Vin Well-Known Member

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    Erik,

    Do you have a VCR that you can use to try Jerome's hook-up?

    The secondary TV in my kitchen is connected similarly: after the coax exits the satellite receiver in the living room it goes to a splitter that feeds the primary set's VCR, then TV. The other line from the splitter runs to the secondary set in the kitchen, ENTERS the VCR (which acts as the modulator), then goes to the TV.....the PQ on the secondary set is very good.

    I think this might be worth a shot if you have a VCR laying around.

    Vin
     
  13. Erik Waibel

    Erik Waibel New Member

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    Hey Vin, it sounds like we have similar setups. Unfortunately I do not have any spare VCRs laying around. I have one on the primary TV in the living room, but it needs to stay there (so my wife can play the kiddie videos for my son). My hookup consists of the composite output of the receiver feeding the VCR (which feeds the primary TV over composite cables). I also have the coax output of the receiver going into a splitter that runs coax to both a 13" Apex in the Kitchen and a 19" Toshiba in the bedroom.

    Now that I think of it...........I wonder if connecting the coax that feeds to the splitter to the VCR coax output (instead of the Satellite receiver) will clear things up. That way I will be using the modulator of the VCR (which is being fed by a short composite run of very good quality cable) instead of the one in the Satellite receiver. I will certainly have to give that a go tonight!!!!
     
  14. Jerome Grate

    Jerome Grate Well-Known Member

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    Depending on what model sat receiver you have, I realized that certain models allow you to use S-VIDEO and Composite video at the same time. If this is the case and you have S-VIDEO available then by all means use it for the main t.v.
     
  15. Wes Goff

    Wes Goff Member

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    I install sats for a living. If your secondary tvs have a composite input, use that. just run another line for audio(it will be a mono sound, but thats what your getting anyway with coax.) they have adapters that go from coax f-pin to rca.
     

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