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When one SWiM isn't enough

Discussion in 'DIRECTV Connected Home' started by veryoldschool, Jul 18, 2012.

  1. Mar 14, 2013 #41 of 111
    SomeRandomIdiot

    SomeRandomIdiot Godfather

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    In the jpg shown in post #1 (and above), if one had a position open on the 4 way splitters, couldn't you just interconnect the SWiM clouds from that point instead of using the 4 additional 850-2150s, which in theory would result in less signal loss?
     
  2. Mar 14, 2013 #42 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Absolutely Not.

    Combining two SWiMs without using diplexers causes the two SWiMs to interact, "in very bad ways". If you don't use the correct diplexers this has happened too.
     
  3. Mar 15, 2013 #43 of 111
    HoTat2

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    Los...
    This is my main concern as I'm considering reducing losses on my setup through both changing out my two 8-way splitters on each leg of the SWiM-16 from the original install for two 4-ways, as well as bypassing the internal DECA crossover on the -16 with two cross-connected diplexers.

    However dielray once told me to be careful to use the right dipelxers, particularly in regard to their ability to suppress any leakage of the 2.3 MHz SWiM control signal to the OTA ports which the DECA signals are using wreaking havoc with the alternate SWiM-8 circuit.

    Was considering this one by Sonora DA;

    [​IMG]

    Sonora SWM/CATV Horizontal Case (SD SWMD2)
     
  4. Mar 15, 2013 #44 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    The NAS STD-9501M is $6 and is known to work, while the Sonora is $10 and "should work".
     
  5. Mar 15, 2013 #45 of 111
    HoTat2

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    Los...
    Well the one in the photo is Sonora's SD-SWMD2 for $5.40 each (at Satprotv anyway). Are you referring to their SD-SWMD3 from Solid Signal for $10.99?

    [​IMG]

    Thought that one would be unnecessary overkill for double the price.
     
  6. Mar 15, 2013 #46 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    SS lists the SD-SWMD2 at $10.
    If the SD-SWMD1 was still available it would be a better choice, which leaves the SD-SWMD3 @ $11 as the only choice from Sonora.

    The NAS diplexer is the only one that has been tested in this configuration.

    Sonora "may" have a product that works, but without testing, I won't say they do.
     
  7. Mar 15, 2013 #47 of 111
    HoTat2

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    Los...
    Though I must say that after looking at this illustration from Sonora DA, I'm not sure I want to spend some $22.00 on these expensive diplexers if all I can expect is around a modest 3 db of gain (-7 to -4 db) through bypassing the internal DECA crossover bridge of the SWiM-16 with these diplexers.

    [​IMG]

    Is that about the same gain I can expect with the NAS diplexers?
     

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  8. Mar 15, 2013 #48 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    The crossover has about 6 dB loss, and the NAS when in bridging mode, has about 1 dB, so there's a 5 dB "gain" for DECA.
    When you move to combining two SWiM-16s, with a 4-way, the "plus" 5 dB drops to -5 dB due to the 4-way loss.
     
  9. Mar 15, 2013 #49 of 111
    HoTat2

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    Ok;

    I once experimentally measured the loss of the -16 internal crossover, and it was indeed about -6 db, but I was simply using Sonora's quoted figure of -7 db anyhow in case I made an error since they are the experts with the professional test equipment. :)

    [​IMG]
     

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  10. Mar 16, 2013 #50 of 111
    ndole

    ndole Problem Solver

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    I can attest to that :lol:
    Spend the money on the correct diplexers.
     
  11. Mar 16, 2013 #51 of 111
    Scott Kocourek

    Scott Kocourek Well-Known Member

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    We never did get to see the back of that setup
    :lol:
     
  12. Mar 16, 2013 #52 of 111
    P Smith

    P Smith Mr. FixAnything

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    Just curious: is SWiM signal going so high - 1.84 GHz ?
     
  13. Mar 16, 2013 #53 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    yes.
    9 100 MHz "channels" starting just below 1 GHz.
     
  14. Mar 16, 2013 #54 of 111
    HoTat2

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    102 MHz to be exact. :)

    But don't know why the seemingly trivial additional 2 MHz is for though.
     
  15. Mar 16, 2013 #55 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    [side note/question] Do you ever read PMs?
     
  16. Mar 16, 2013 #56 of 111
    P Smith

    P Smith Mr. FixAnything

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    perhaps 2 MHz is guard gap, and one "channel" taking up to 100 MHz ?
     
  17. Mar 16, 2013 #57 of 111
    HoTat2

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    That's what I once considered P. Smith

    But with the satellite transponders 24, 36, and 62.5 MHz wide, there would seem to be a lot of remaining space from 100 MHz for guard bands without the need for an another 2 MHz.
     
  18. Mar 16, 2013 #58 of 111
    P Smith

    P Smith Mr. FixAnything

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    We need to know SWiM type of modulation (forget about tpns with 62.5 MHZ width - no one tuner H/HR and dish STBs support it !); is it QAM-1024 ?
     
  19. Mar 16, 2013 #59 of 111
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    "It would seem" to be just what the tps use and this is merely a frequency shift.
     
  20. Mar 16, 2013 #60 of 111
    P Smith

    P Smith Mr. FixAnything

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    I could make sweeps with spectrum analyzer and post them here, if someone will throw away "old" SWiM LNBF or SWM-16 (to connect it to my AU-9 LNBF) ;) ...
     

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