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A lot of cascading... Lower signals?

Discussion in 'DIRECTV Installation/MDU Discussion' started by inkahauts, Oct 18, 2008.

  1. inkahauts

    inkahauts Well-Known Member

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    Ok ,so I am curious as to what you guys think...

    Here is a setup...

    Slimline dish 4 runs to a WB68

    4 outputs from WB68 to a SWM5

    (SWM5 is run and split to two HR20's, utilizing 4 of 5 "channels")

    Other 4 outputs are run to a second WB68...

    4 of the outputs from the second WB68 go to an HR20 and a HR10

    The other 4 feed a WB816.

    All outputs on WB816 are being used as well...

    Runs from Dish to first WB68 is 50 feet.

    Run from first wb68 to swm and second wb68 a couple feet. all runs from swm5 and second wb68 100 feet

    All runs from WB816 are about 6 feet...



    So do you guys think that this setup would loose signal strength? Which outputs? Do you think KA would loose more than KU? Hi vs. Lo?

    If I insert a signal meter next to the dish on one of the lines, will that signal be the same, or higher than what I get on the all the boxes?
     
  2. David MacLeod

    David MacLeod New Member

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    I'm a newbie so forgive any errors.
    if I understand right one of the wb68's has all its ports used just to feed other (swm5 and other wb68) switches. while other wb68 loses half feeding wb616 so in effect you're losing 12 tuners in the process.
    if I read right you're actually using 24 tuners, 4 from swm5, 16 from wb616, and 4 from 1 of the wb68.
    can't you get a smw 8, parallel it with a wb616, and have the same amount of tuners with 2 less switches?
    I would think that with that many switches the CHANCE of a loss is high.
     
  3. houskamp

    houskamp Active Member

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    my question is is this a hypothetical setup or do you have this mess? :grin:
    It would be much better with the wb616 right off the dish.. and problably also a second wb616 instead of the 2 wb68s.. or a set of SWMs off a wb616..
     
  4. carl6

    carl6 Moderator Staff Member DBSTalk Club

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    Get four 3 port, all port power passing, splitters. Run the SWM, WB68 and WB616 all in parallel directly off the splitters. From your description, all switches are in the same location so that shouldn't be a problem.

    Carl
     
  5. Teronzhul

    Teronzhul Godfather

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    At this point, maybe he should just get a second dish.
     
  6. David MacLeod

    David MacLeod New Member

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    lol, or 6 less tuners :)
     
  7. rudeney

    rudeney Hall Of Fame

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    +1

    Remember that every time the signal is split (either by a splitter or multiswitch) there is a loss in signal strength. A cascaded split causes twice as much loss as a parallel split.
     
  8. texasbrit

    texasbrit Well-Known Member

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    Unless the signal is very weak because of very long cable runs the splitting should not cause a problem, although it is a factor to consider. The problems with cascading are nearly always power drop to the LNB or signalling voltage drop on the 18v necessary to select even transponders; these problems usually happen long before you will see any signal "strength" reduction.
     
  9. texasbrit

    texasbrit Well-Known Member

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    Unless the signal is very weak because of very long cable runs the splitting should not cause a problem, although it is a factor to consider. The problems with cascading are nearly always power drop to the LNB or signalling voltage drop on the 18v necessary to select even transponders; these problems usually happen long before you will see any signal "strength" reduction.
    inkahauts solution will probably work OK, although it's messy. IMHO Carl's solution is much tidier. I assume there are four cables to some other part of the property where the WB616 is located. If that's the limitation, another solution would be:
    Splitters in the cables from the dish driving two WB68s in parallel. One WB68 cascades down to the SWM5. Second WB68 cascades down to the WB616. 13 outputs in the first location, 16 in the second. Only one level of cascading.
    Or junk the WB68s and get another WB616. Cascade it down to the SWM5 and to the second WB616. Again, 13 outputs in the first location, 16 in the other.
     
  10. 50+

    50+ Legend

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    I have set up a swm8 cascaded off a wb68 at my daughters house. It works great.

    In another thread I thought I read that the power inserter off the swm8 would power or help power the wb68, I might have dreamed this.

    If this is the case the power drop should be minimal. Has any one else heard this? Does this have any connection to inkahauts situation.
     
  11. houskamp

    houskamp Active Member

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    I had that setup for quite a while.. at least that's only one level..
    I have seen official stuff that says you can run 4 WB616s off one WB616.. 64 tuners :eek2:
     
  12. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    At some point there will be a RF level problem. While the DC will power the LNBs, how many times can you "split/select" the same signal, before the loss becomes "significant"?
     
  13. inkahauts

    inkahauts Well-Known Member

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    Yeah, real setup at the moment... Its a temporary fix for a couple months, so didn't want to deal with rewiring the house, and number of lines run limit where I can place different switches/spliters... and again, for only a couple months...

    Its working... good siganls... but not overly fantastic... (can't get higher than low 90's on 101, mid 80's on 103, 99, and there is farily large range between highest and lowest signals... almost 15 points on some transponders) and was curious if anyone thought this would cause massive signal issues... I can say, at the moment, its not... And its not like it rains in LA...

    Thanks for the imput guys! :D
     
  14. paulman182

    paulman182 Hall Of Fame

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    The 64-tuner install is diagrammed in the WB616 manual that is online.
     
  15. evan_s

    evan_s Hall Of Fame

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    If nothing else the first WB68 should be able to be replaced by 4 splitters since it's just running 2 multi switches. Just make sure you match up the inputs on the 2 multiswitches for voltage tone/no tone. That would also eliminate the cascading of 2 wb68s but I don't think thats actually likely to be causing problems with both a WB616 and a SWM5 in the mix to help power the other multiswitches.
     
  16. claycruncher

    claycruncher AllStar

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    I am changing my configuration of cascading 2 wb616 to running them in parallel based on the advice of many on this forum. However, if I don't connect the second wb616 to the satellite feed splitter (Skywalker 5 - 2300 MHz) do I need to terminate the unused port of the skywalker splitter until I have a need for the second multi switch? I know the WB616 says not to terminate any unused ports on it, but what about the unused port on the Skywalker?
     
  17. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Since the Skywalker splitters are "diode steered", the voltage won't go to the termination and the RF will and it won't reflect [back], so it sounds like "good house keeping" to do it.
     
  18. rudeney

    rudeney Hall Of Fame

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    My understanding is that unused ports on a non-SWM system should NEVER be terminated.
     
  19. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    This is true, so the DC voltage doesn't go into the 75 ohm resistors.
     
  20. LameLefty

    LameLefty I used to be a rocket scientist

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    Middle...
    Good old V=IR

    Hey, I remember SOME of my EE and physics classes. :lol:
     

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