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Mutlti-switch question

Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by Rich, Aug 10, 2008.

  1. Rich

    Rich DBSTalk Club DBSTalk Club

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    Can someone come up with an easy to understand explanation of how the Zinwell multi-switches work and the difference between the "powered" 6x16 and the "passive" (I do understand that the DVRs supply the power for this switch) 6x8?

    I have spoken to the Zinwell folks a couple times and they expressed a preference for the 6x16 when cascading multi-switches. That leads me to believe there is a tangible difference between the two. And I have read posts that suggested that cascading 6x8s was not a good idea.

    It seems as if I read more and more about multi-switch usage and have never seen a thread or post that explains what the multi-switch does and how it does it.

    I had one Channel Master SD multi-switch go bad. It kept switching constantly and played havoc with the six (I think) TiVos hooked up to it. Bought a new identical unit and the TiVos worked perfectly. I knew how to solve the problem, but I still don't understand what happened to the Channel Master that went nutz.

    Please, use the KISS method. I don't understand things like "they attenuate the waveform of the grabistan."

    Thanx,

    Rich
     
  2. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    It's all do to the phases of the moon.

    The non-powered WB68 uses the 13/18 volts and 22 KHz tone to switch the output to the correct input AND power the dish which has a multi-switch also which then powers the LNB.

    A WB616 uses the receiver voltage/tone to select the right input. Here is where the difference comes in. The WB616 power the dish, just like using a Sonora locker.

    Cascading WB68 simply add more to the chain causing a loss to the final dish.
    Think of a WB616 as being two WB68 in parallel with 2-way splitters and a Sonora locker "in one package".
     
  3. houskamp

    houskamp Active Member

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    powered: switch has it's own power and powers the dish..
    nonpowered (passive): switch uses reciever to power both dish and switch..

    Basicaly all switches do the same thing.. They lock each of the inputs to one of the 4 combinations.. this makes each combo availible at the switch.. then when the reciever asks for one of the four, it selects that one and sends it to the requesting reciever..
     
  4. bobnielsen

    bobnielsen Éminence grise

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    The multiswitches allow one to have multiple receivers which can receive a choice of several satellite and polarization combinations by sending a signal to the dish/multiswitch.

    For a 3-LNB dish, these are
    101 odd (13V)
    101 even (18v)
    119 odd (13v, 22 kHz)
    110/119 even (18 v, 22 kHz)

    110 has a special LNB which is combined with the output of the 119 LNB such that the channels don't interfere with each other.

    99 uses the same logic as 101 with a different LNB output frequency.

    103 uses the same logic as 110/119 with a different LNB frequency.

    The multiswitch detects the voltage and presence/absence of 22 kHz and chooses which LNB to connect to the receiver. This is for the multiswitch which is built into the dish.

    An external multiswitch has 4 inputs corresponding to each of the above conditions and switches the desired input to any of the 4/16 outputs depending on the signal received from the satellite receiver. The WB68 just passes the voltage levels through to the multiswitch on the dish, while the WB616 has a power supply which supplies the necessary signals to the dish. With the WB616 the system will be less critical as to voltage drop in the cables, etc.

    The SWM multiswitch operates differently.
     
  5. carl6

    carl6 Moderator Staff Member DBSTalk Club

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    Further, if you are using all non-powered multiswitches (such as two WB68's either in parallel or cascaded), based on what channels your receiver(s) are tuned to, you could easily have one or more of the four voltage/tone combinations not present at any given time.

    Carl
     
  6. Rich

    Rich DBSTalk Club DBSTalk Club

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    Actually, that's easier for me to understand.

    What is a "tone"? The frequency thing I get, the "tone" thing I don't.

    OK, that I knew. Feeling better now.

    "Voltage/tone". The frequency and voltage are equatable? What is a "Sonora locker"? Feeling dumb again.

    OK, that I knew. Feeling better now.

    Followed that right up to "Sonora locker".

    Rich
     
  7. Rich

    Rich DBSTalk Club DBSTalk Club

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    OK, that I knew.

    That whole statement went right over my head. Perhaps the Puddy Tat could dumb it down a bit?

    Rich
     
  8. houskamp

    houskamp Active Member

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    Think of it this way:
    Butcher at the store (multiswitch) with 8 coustomers at he counter..
    Since he doesn't know what his coustomers want he has to have availible all 4 types of meat (fish,pork,beef,seafood).. this would be the 4 lines from the dish..
    when a coustomer comes to the counter asking for one of them he "hooks them up"

    If he only had 3 lines he couldn't serve all his coustomers..

    there are basicaly 2 different voltages and 2 low freq tones (22k?) that "set" the
    switch..this gives four combinations..


    I tried :lol:
     
  9. Rich

    Rich DBSTalk Club DBSTalk Club

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    So, to give the 20/21s personalities, the 20/21 sends a signal to the multi-switch which then sends a signal to the built in multi-switch in the dish asking for a particular combination of signals that will show up as a program for the DVR to record? Or a plain receiver to display that requested program? Have patience with me, this is confusing.

    What does a 5LNB look like, using the above model?

    So, I guess that as soon as I get an explanation of the "tone" I should begin to understand what the frequency does?

    OK, that I understand. And the 6x8s, because they are not powered by another source not connected to the 20/21 should not be cascaded, because of the voltage drop experienced in multi-room, multi 20/21 hookups, is that correct?

    When I began to rebuild my "system" so that my 21-700 would work correctly, the first thing I did was replace a 6x8 that was cascaded from a 6x16. The next steps were replacing the dish and subsequent realignments and recabling. If I had to guess at what caused the stability to finally take place, I would think it was a combination of the above steps rather than one particular step.

    Which brings me to another question: Is it feasible to cascade a 6x8 from a 6x16? I know it works all right with 20-700s, but the last spate of problems I had were only with the 21-700.

    Let's leave that for a future thread. The whole multi-switch thing needs more clarification before I tackle a new technology. But, I gotta ask, is SWM better or more convenient?

    Thanx for the good info,

    Rich
     
  10. evan_s

    evan_s Hall Of Fame

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    It is a little complicated to understand but basically the dish only gives you 1/4 of the possible channels at a time on any one output. A multiswitch works by taking the 4 outputs of the dish and setting each one of them to a different quarter of the channels which collectively allows it to get all the possible channels. It then takes and passes out which ever 1/4 of the channels each output selects allowing you to use more than 4 receivers. You can't just split an output normally like you do with cable because the 2 different receivers might be looking for channels from different groups and wouldn't be able to see both at the same time.

    The 13/18volt and no tone or a 22khz tone are how it signals which of the 4 options it wants.
     
  11. Rich

    Rich DBSTalk Club DBSTalk Club

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    One of the reasons I started this thread was because I wondered how many people had 6x8s cascaded or paralleled and were having troubles that could be caused by cascaded or paralleled (I gather you have to use splitters to parallel the switches?) multi-switches.

    So, cascading or paralleling 6x8s is just plain bad, right? I remember reading somewhere that the splitters should be avoided if possible.

    My first thought when I originally cascaded the 6x8 off the 6x16 was that the 6x16 would provide the power for the 6x8. I gather I was wrong?

    Rich
     
  12. harsh

    harsh Beware the Attack Basset

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    Don't forget the complication of polarity.

    The key words in this are:

    1. Low Noise Block converter
    2. Polarity
    3. Stack plan
     
  13. harsh

    harsh Beware the Attack Basset

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    Cascading is bad with non-powered multiswitches as the power coming to the switch closest to the dish is partially consumed by the near-side switch.

    Paralleling switches is a generally accepted way of getting more outputs.

    Splitters can only be used in a parallel situation. They cannot be used for any other purpose in the context of a legacy multiswitch.


    Are you trying to give yourself a headache, or do you really need more than 8 ports?
     
  14. evan_s

    evan_s Hall Of Fame

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    essentially yes but what actually happens is each of the 4 inputs on the switch is always asking for one of the 4 combinations and it just routes the correct input signal to the correct output port(s) based on the signal coming in on that port.
    The 5lnb dish adds 99 above and below 101 with odds and evens the same way. 103 is the same way with 110/119.
    Tone is just a way of saying it puts a 22khz frequency on the line.
    A 6x8 cascaded off a 6x16 should work just fine. The 6x8 would end up being powered by the receivers connected to it and the 6x16 would still be powered by it's power supply so the receivers are only powering a single 6x8 in that situation.
    SWM has some definite advantages over the current system. It allows a single cable to support up to 8 tuners and can be split like a normal cable signal can. The way this works is instead of getting a 1/4 of the channels on the cable at a time and just selecting one of the 4 quarters the receiver asks for a specific block of channels, say 4 or 8 channels that are all broadcast together, and it allows the switch to put 8 of these blocks on a single output. Each tuner just gets one of the blocks to listen to and gets what ever channel it needs put in it's block. Obviously this requires a more complicated switch and more complicated communication between the receiver and switch which is why it's a new and currently more expensive option but that will change.
     
  15. Rich

    Rich DBSTalk Club DBSTalk Club

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    And you did damn well! This post should be the model for a "KISS method" post. That is what I was looking for.

    So, the processors in the 20/21s determine which voltage and whether a "tone" is required to "ask" the dish for a particular satellite feed? And if that is correct, how does the 20/21 select the program from the sat feed?
     
  16. evan_s

    evan_s Hall Of Fame

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    It knows where to find the channels based on the info it gathers via the sat feed. I believe thats primarily what is happening when it's acquiring sat info during the boot process. Gathering the info on what sats and frequencies all the channels are on. This info gets updated continuously while the receiver is on.
     
  17. Rich

    Rich DBSTalk Club DBSTalk Club

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    Evan, I know you tried, but that is just too confusing for me. I read it four times and I don't get it. The splitters and the usage of them I am familiar with. Could you "dumb" the rest down a little. Remember, you know what you are talking about, I'm trying to digest this and simpler is easier for me.

    I got that.

    Rich
     
  18. Rich

    Rich DBSTalk Club DBSTalk Club

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    Talking about the splitters?

    Rich
     
  19. houskamp

    houskamp Active Member

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    There is a part of the satalite transmissions that contains a "phonebook" of what is on and where it is..
    Going back to my previous example:
    Coustomer (reciever) asks for a fish (voltage/tone combo).. It already knows whether it needs the tail, head, or body (transponder) to make it's "recipe" (channel)..
     
  20. veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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