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RainFade - Need solution

Discussion in 'DIRECTV General Discussion' started by Davenlr, Jun 20, 2010.

  1. Davenlr

    Davenlr Geek til I die

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    Sep 16, 2006
    Ok, After putting up with this for years, Ive finally had it. Almost every day, we have pop up thunderstorms, and they always seem to pop up in the middle of a baseball game, or Nascar race.

    I can switch to the SD channel on KU, and watch, but the HD channels are 771 for 15 to 45 minutes at a time.

    Clear weather signal strength on 99 and both 103's is 90-95.

    Has ANYONE on this forum in the CONUS, installed a Hawaii 99/101/103 dish to increase the signal on the KA sats, and what luck have you had? If I cant get this problem solved soon, Im just going to sub down to the basic cheapest package I can to continue getting MLBEI, and add Comcast for HD.
     

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  2. Kevin F

    Kevin F Hall Of Fame

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    May 9, 2010
    You could have water in the coaxial line. Its a possible problem that I have dealt with before.

    Kevin
     
  3. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    About the most you could do is go with the 1.2 meter dish and use the SWiM LNB. the dish will add a few dB and the SWiM can add another 10-15 dB as the levels drop, which might reduce the fade.
     
  4. texasbrit

    texasbrit Well-Known Member

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    The extra few db you get from the dish is not going to make much difference at the Ka frequencies used by the HD signals. The attenuation at Ka from a severe thundercell is far higher than the larger dish can compensate for. As VOS says, using an SWM system can possibly help because of the automatic gain control but AGC can't produce a signal out of nothing.
     
  5. eakes

    eakes Godfather

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    Sep 21, 2007
    Sorry, but it is impossible to get a large enough dish to eliminate rain fade problems. I have a 6 foot diameter KU dish that I installed a Directv LNB on a few years back. I was also using a 3 LNB dish at the same time. I had one receiver connected to the larger dish and four to the standard dish, all displaying to individual TVs in my den. During a heavy thunderstorm all receivers would lose signal. The receiver on the large dish would 'stay in' a few seconds longer and recover a few seconds earlier than the other receivers, but it always lost signal in concert with the other receivers.

    The SD channels are on 101 (primarily) which works at 12 Ghz, the HD locals (and other HD channels) are on 99 and 103 satellites which work at 18 Ghz. As should be expected 18 Ghz is much more susceptable to rain fade than 12 because higher frequency means shorter wave length which has more problems with a 'wall of water' between the transmitter and the receiver.

    If one tries to get an antenna much larger than 6-8 foot diameter, there is another problem - too much signal during normal conditions. Digital receivers work best when the received signal lies within the design parameters of the receiver. When the received signal is too strong the bit error rate of the receiver increases which, from the viewers perspective, gives the same result as too little signal (ie, rain fade). Thus, if one connected a 200 foot diameter dish to the receiver during rain fade conditions, the video might not go out. But as soon as the rain goes away the video would go out because the received signal is now too strong.

    Avoiding rain fade would mean repealing a couple of laws of physics which no one has been able to do. If one absolutely cannot not tolerate any rain fade outage, then I would suggest FIOS!
     
  6. AMike

    AMike Godfather

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    I may not exactly understand the technology and it's been 11 plus years since I had cable, but why does this not occur with cable since they are getting most of the signals off satellite as well. Granted, the dishes that I have seen cable companies in the past use were as big as a house, but rain fade was never an issue. The only issue I recall when I had cable was during certain times of the year when the satellite signal would go out due to solar activity.
     
  7. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    The lower that SAT frequency used the less rainfade. There are a few maybe 2 & 4 GHz [it's been a long time and I'd need to dig out some very old notes] that have very little fade. Add to this they use large dishes and this should reduce most of this.
     
  8. Davenlr

    Davenlr Geek til I die

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    Cable uses the 3.5 to 4 Ghz "C" Band, which has relatively no noticable rain fade when using a dish of 10 - 16'. In fact, when these thunderstorms pop up, thats exactly what I do (assuming the channel I am watching the race/game on is a network channel), I go to the Puerto Rican cable feed for the network, or the main network feed itself using a 6' C band dish, and continue to watch until the storm passes.

    Ive read all the posts (I am already using SWM), and while I agree 18Ghz is more attenuated due to raindrops, I also recall that when we had only 101 KU, I had a 36" dish (vs everyone elses 18" dish), and RARELY did I get any signal interruptions. Thats why Im thinking a 1.2M Hawaiian dish might work, since the signal is SO CLOSE to being receivable (close enough the 771 message pops on an off the screen, and the picture pops in and out, pixellates, etc). Its not a complete loss for 15 minutes. Im thinking if I could add about 3db of REAL gain to the LNB, it should eliminate about 75% of my outages.

    Thats why I am curious if anyone is USING a Hawaiian dish in the conus right now. Im past theory, and looking for some real world results. FWIW, I have a 1.2M KU dish I could use to experiment with, however, Id need to modify the mount, and Im sure since the dish is a standard offset, I wouldnt be able to tune in more than one satellite at a time, unless I got just REALLY lucky, so I havent tried that yet.
     
  9. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    What are your clear sky signal strengths? In theory I have a longer look thru the cloud layers than you do. Yet I do not have any rain fade. (Just ice fade a couple times a year.) :)

    Now, I could be lucky and have just the right angle to miss any big storms to the south-east since this is a semi-arid climate right here.

    Cheers,
    Tom
     
  10. Davenlr

    Davenlr Geek til I die

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    99c
    87 88 85 89 83 85 85 88
    83 87 86 89 86 89

    103ca
    95 95 95 94 92 94 91 95
    90 94 94 92 91 93 95 95

    103cb
    89 92 89 92 84 89 86 91
    84 89 88 91 82 88

    Dish was fine tuned to 99c's lowest reading transponder.
     
  11. Tom Robertson

    Tom Robertson Lifetime Achiever DBSTalk Club

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    Wow, that is better than I got.

    Now I'm wondering about something else in the infrastructure as has also been suggested.

    Good luck,
    Tom
     
  12. Davenlr

    Davenlr Geek til I die

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    Its pretty straightforward. AU9 with a Eagle Aspen SWMLine5, 50' RG6QS to power inserter, 3' RG6 from power inserter to DirecTv 8 port splitter, 25' runs of RG6 to 5 locations, and a 6th RG6 run to the internet DECA. Two unused ports terminated. Pretty straightforward. I cant think of anything else to do.

    FWIW, my parents 4 blocks down the road lose signal within minutes of me, and get it back within minutes of me, so its defiantly the rain fade from the thunderheads (hell, it didnt even rain here today, yet lost signal for 15 minutes).
     
  13. webby_s

    webby_s Hall Of Fame

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    99c
    94 94 84 85 90 91 80 83
    89 93 81 85 92 95

    103ca
    95 95 91 92 91 94 88 92
    88 93 88 91 87 88 89 89

    103cb
    95 95 91 91 91 91 91 92
    91 91 92 93 91 94

    These are all after I peeked the dish myself and cut down branches that were in the way after the leaves grew back in the spring (ash tree)

    The two times I lost signal, one was when we got an inch of rain in about an hour. The second was when a tornado landed about 6 miles to the north and west of me for about 8 blocks (4 days ago) (no one died thank goodness)
     
  14. johns70

    johns70 Legend

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    You can try putting a pole in the yard to mount the dish on that would put the dish above the clouds.
     
  15. jaywdetroit

    jaywdetroit Hall Of Fame

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    I was dealing with increasing rain fade as well, (I imagine I could have had my dish tweaked, but still...)

    I am VERY happy with my solution. It's cheaper, more reliable, faster, and I get more HD...

    http://www.dbstalk.com/showthread.php?t=176777
     
  16. Davenlr

    Davenlr Geek til I die

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    Im already using your solution. I have a HDHomerun(2), SageTv, internet tv, C band satellite, KU Satellite.... Except for one problem. None of the above solutions will show HD baseball and Nascar races (I actually havent tried MLB over the internet, it *might* be HD). Seems despite the bombarding of the viewer with advertising during a race, on the track, on the cars, on the uniforms, NASCAR has required their feeds be scrambled this year...So, DirecTv is about the only source for the races in HD.
     
  17. jaywdetroit

    jaywdetroit Hall Of Fame

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    Yep - MLB baseball was one of my biggest reasons for continuing to pay for TV service. I don't watch NASCAR, so that is non-issue for me. Good Luck!
     
  18. dennisj00

    dennisj00 Hall Of Fame

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    Lake Norman, NC
    Someone used the term 'wall of water' and it's literally a 'lake' of water that the signal has to go through. Your dish is looking diagonally through this lake of water in the sky.

    I use the rain fade somewhat as a prediction if the storms are moving from the SW. When they are, I generally get the fade before it starts raining and it can be
    'raining cats and dogs' (my Davis weather station actually says that!) here and I get the pic back.
     
  19. azarby

    azarby Hall Of Fame

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    !rolling!rolling
     
  20. jefbal99

    jefbal99 Hall Of Fame

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    would be a pain trying to keep that thing stable and plumb in the wind ;)
     

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