771 HD channels in MDU

Discussion in 'DIRECTV Installation/MDU Discussion' started by Rookie tech, Jul 10, 2020.

  1. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    hey is there anybody can tell me what's going on in this system?...I have an MDU system with sonora polarity locker wich I replaced last week because HD channels were failing with freeze and pixelation and 771 as well...those channels specifically are 360 FX news 356 MSNBC...I have checked with my AIM and the 4 wires before sonora polarity locker have been passed EIV plus succesfull
     
  2. slice1900

    slice1900 Well-Known Member

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    Well channel 356 is 103cb and 360 is 99cb so that rules out a lot of problems right there.

    How long are the outages, are they just a momentary hiccup or do they last longer? If it is a quick outage I'd say try replacing the power supply for the polarity locker. Perhaps it is starting to fail?

    If that doesn't do it, or the outages are longer check the dish and area around it. Maybe something is temporarily obstructing it like birds flying in front of it if there's a nest nearby or even roosting on the LNB arm.
     
  3. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    its happens randomized
     
  4. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    I just replaced the polarity locker but I never check the 24 V power supply...do I need to check just the voltage or the AMPS is better to measure at the end
     
  5. slice1900

    slice1900 Well-Known Member

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    I would just replace it, an item that cheap it isn't worth the time to test and even if you do there's no guarantee it'll act up while you are testing it. If the problems persist after replacing it at least you've ruled out something else.

    You might also want to be sure about what it is plugged into if there's any reason to suspect the quality of power in the building. A regulated switching power supply like Sonora makes should withstand momentary brownouts without trouble, but if you are plugged in on the same panel as something really big like a 100 ton HVAC unit brownouts might be more than 'momentary'.

    If you know around when the problems started you might want to contact whoever is responsible for building facilities and ask them if there has been any electrical or electrical related (like HVAC repair/replacement or whatever) work done involving the panel your polarity locker is plugged in on around the time the problems started.
     
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  6. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    Hey can I use a 29 V PI instead of 24 V power supply?both ending in F connectors
     
  7. slice1900

    slice1900 Well-Known Member

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    You can but Directv's 29v (and 21v) power supplies are not auto regulating so I wouldn't use it in such an important role in an MDU long term. I'm sure some people do and it works for years so it isn't like it is a disaster waiting to happen but auto regulating power supplies are built to a higher quality standard and you don't want a failure to knock out an entire building's TV.

    Its fine to try the 29v and see if the problems go away, but if they do order a replacement 24v from Sonora and swap it out for the long term.
     
  8. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    Hey slice Thanks for your response I just checked the 22 kHz in the wire number 3 before swim32 and wasn’t detected I replaced the 24 V power supply for a new one and same things... then putted a new polarity DTV6PWRPOL-02 on the unit and still was failing the 22khz but in one of the genie IVRtest passed successfull I have not any idea what’s happening
     
  9. slice1900

    slice1900 Well-Known Member

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    When you are using a polarity locker the SWM switches (SWM32 in your case) is not powering the dish, so measuring the 22 KHz tone between the polarity locker and SWM32 is pointless since any voltage or tone is blocked by the polarity locker and its own voltage and tone outputs substituted.

    Since you've replaced the power supply I guess just wait and see if the 771 problems are still present. Also how many SWM32s or other SWM switches are there and how are they connected? i.e. taps, splitters, etc.
     
  10. Rookie tech

    Rookie tech New Member

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    Jul 10, 2020
    ok I understood about the measurement of the 22 khz tone I thought that at the output of the polarity locker you could see those values in the AIM and that's why it was my confusion ... really when I measured the old 24 V power supply it was giving me 27 V So it was in parameters and really when I replaced it with a new one I did not check again if the 771 appeared on the screen or not only let me be guided by the AIM however since I changed the polarity locker I have called several clients and they have told me that the service has been more stable the configuration that this building has is the following 2 satellite dishes 1 National SL5 and other one 95 for internationals programming after those 5 splitters to divide the 5 signals because there are two wings one north and one south in the north branch is the one that was giving the problem ... in that branch there is a ground block in which the signals passed well according to the EIV plus later there is the polarity locker before it was a Sonora now it was replaced by a DTV6PWRPOL 02 after this there is an MST771 tap that feeds the SWIM 32 of that first floor (Penthouses) and feeds the lower floor unit that has another MST771 Tap that also feeds the 17th floor unit then there is the 16th floor which is the same as the 17th and the first amplifier is on the 15th floor all units have the same Tap MST771 and swim 32 but I don’t know If I founded the problem I’m sure it was in the polarity locker because the service is more stable but what happened was a freeze and pixelation on many HD programming like channel 360 356 somes HBO etc
     
  11. HoTat2

    HoTat2 Hall Of Fame

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    Also, and I realize slice may disagree with me, ....

    Personally, I've never fully trusted the diode steered wideband power-pass splitters for feeding the inputs to parallel multiswitches or their backbone distribution networks feeding them as in your case.

    But while keeping the splitter for the 95W dish in your situation, prefer using a WB68 multiswitch for the four lines from the SL-5. With four outlets from the multiswitch feeding the north PL and the other four to the south PL.

    This wouldn't be officially approved by DIRECTV for MDU installs of course, but from what I've read on the past experiences of others with such issues, works better and is more reliable.

    Sent from my LM-V600 using Tapatalk
     
  12. slice1900

    slice1900 Well-Known Member

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    You would see the 22 KHz at the OUTPUT (or "top" i.e. the other opposite the side closest to the receivers) of the polarity locker - i.e. towards the dish. You should have a setup something like:

    dish -> polarity locker -> splitters to north/south wing -> taps -> SWM32s

    Your description is a little hard to follow (maybe you can make a drawing?) but it sounds like you have two polarity lockers? Or you have the polarity locker after the splitters in only one wing? If so that is VERY wrong.
     
    Last edited: Jul 12, 2020
  13. slice1900

    slice1900 Well-Known Member

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    The only possible benefit of using a WB68 in this way is to avoid multiple switches sending out potentially conflicting 22 KHz tones, which is what the polarity locker avoids. If you have a polarity locker it doesn't matter if you use a WB68, have diode steering splitters or regular splitters or even non power passing splitters since the DC blockers at the "bottom" side of the polarity locker (away from the dish towards the receivers) blocks all power and 22 KHz tones anyway.
     
  14. HoTat2

    HoTat2 Hall Of Fame

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    Yes, I noticed that too ....

    Sounds like the OP's setup has two PLs, plus has the power-pass splitters positioned before the PLs, both which are really incorrect.

    As there should only be a single PL fed by the SL-5 and 95W dish, and then five of the outlets from the PL feed the five power-pass splitters.

    Which then feed the inputs to the first multi-taps of the north and south backbones.

    Sent from my LM-V600 using Tapatalk
     
  15. HoTat2

    HoTat2 Hall Of Fame

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    Oh, yeah slice I realize this too now ....

    The PL, if positioned correctly as the first in the chain after the LNB, would indeed make diode steered and/or power-passing ability of the broadband splitters or the use of a WB68 instead, really irrelevant.

    But when I posted my preference for the WB68 I was basing it on the OP's apparent description of having the PLs for the north and south backbones placed after the splitters. When I should have realized that is the wrong hookup the OP has to begin with.


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