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SD vs HD rain fade

Discussion in 'General DISH™ Discussion' started by splish, Oct 19, 2011.

  1. splish

    splish AllStar

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    It is being presented as fact in the DirectTV forums that the SD signal is more resistant to rain fade than is the HD signal. Is this indeed true, and is it the same for Dishnetwork? Could someone give me an idea of how substantial the difference is, perhaps in signal meter strength?
     
  2. scooper

    scooper Hall Of Fame

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    Youngsville NC
    The issue is more of a frequency band - SD is on conventional DBS, HD (for DirectTV) is on a different band. With Dish - HD and SD are both on the same conventional DBS bands.

    So, for Dish, SD and HD should be the same, given the same transponder signal strength.
     
  3. 4bama

    4bama Godfather

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    Also, don't forget that many, if not most, of Dish's HD feeds are on a different satellite than the SD feeds...

    For example, in my location the 129 bird carries most of the popular HD feeds while the 110 and 119 birds carry the SD and some of the HD feeds.

    During a heavy thunderstorm these satellites will experience signal fade at different times, depending on how the storm clouds are moving...one satellite may lose signals from rain/cloud fade while the other(s) don't..

    Since 129 has stronger spot-beam radiated power (supposedly), I have noticed that with a strong storm moving through my area that 129 is the last satellite to lose signals and the first to regain them as the storm passes.
     
  4. boba

    boba Hall Of Fame

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    DISH uses Ku band signals for both SD & HD. Directv uses Ku for SD broadcasting and Ka for HD. Ka is a shorter wavelength than Ku so at the same power levels Ka fades first. By using stronger signals the Ka can be improved but will still probably fade first. If it never rains in Southern California who cares, now Florida may be a different story.
     
  5. cj9788

    cj9788 Hall Of Fame

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    MiamiFl locals are (last time I checked) on 110 and for the last week we in Miami have seen a deluge of rain and without fail they have gone out while the SD version on sat 119 has not.
     
  6. Laxguy

    Laxguy Honi Soit Qui Mal Y Pense.

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    Winters,...
    Yeah, I have very seldom had drops due to weather in N. CA. As Mr. Hammond says,

    "Seems it never rains in Southern California
    Seems I've often heard that kind of talk before
    It never rains in California, but girl don't they warn ya
    It pours, man it pours"

    Back to topic: Would not SD broadcasts, all other things being equal, be subject to less fade due to their being much smaller streams?
     
  7. satcrazy

    satcrazy Icon

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    Great...
    I'm in NW Pa., and locals on 129 are usually the first to go. I do agree with the fact that different sats fade at different times, as 110 can be working while 119 is out, depending on cloud movement, and sometimes the signal is lost before the rain ever hits the ground. Tech told me 129 is a low sat, so that signal is the weakest. I can still retrieve locals through my converter box during a storm, so his statement must have some truth to it.
     
  8. harsh

    harsh Beware the Attack Basset

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    Salem, OR
    Yes, it is true and no, DISH Network signals are not similarly impacted.
    No. Rain fade differences between frequencies is not something you can readily assign a linear mathematical function to.
     
  9. Stewart Vernon

    Stewart Vernon Roving Reporter Staff Member Super Moderator DBSTalk Club

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    Kittrell, NC
    Also.... while people mostly talk about "rain fade"... I find I'm more susceptible to "cloud fade" than rain fade.

    I have had solid signal in some major downpours here as long as the clouds aren't those dark/thick clouds.

    I can completely lose signal on a non-rainy day if a dark cloud gets in the line-of-sight... but watch when those clouds pass by even if the rain is still coming down.
     
  10. Michael P

    Michael P Hall Of Fame

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    Actually the locals should be the last to go if they are on a spot beam. A spot beam is usually stronger (unless you reside on the fringe of the spot then the opposite is true). NW PA, would that be the Erie, Youngstown OH or Pittsburgh DMA? At one time Erie must have been on 118, I had family just over the state line in the Pymatuning Lake area. As soon as I crossed the state line there was a rash of 118 LNB's. That was the only way they got their locals, due to the ridge the OTA signals from their own DMA barely made it (while some of the Cleveland stations came booming in).
     
  11. good

    good Mentor

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    it might have something to do with channels grouping and FEC?
     
  12. harsh

    harsh Beware the Attack Basset

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    Salem, OR
    It has nothing to do with multiplexing as that is only how the bandwidth is used, not how coherent the signal is. FEC can improve the apparent quality of a signal but it can't create reception where the signal is scattered.
     

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