A question about Signal Strengths

Discussion in 'DIRECTV - Special Request Legacy Items (private)' started by Grentz, Oct 14, 2008.

  1. Grentz

    Grentz New Member

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    I have been active in reading all the info on SWMs and have a pretty good handle on how they work, setup, etc. even helping others get theirs setup and working (even though I do not personally have one yet). I have yet to see info on this though....

    With the SWM and signal strengths, are the signals between the Dish/SWM and SWM/Receivers handled separately and as such do not totally affect each other?

    To better explain what I mean, say you have rain fade that cuts down the signal that the SWM is seeing on the dish side, does the signal then gain additional losses depending on what the signal is between the receiver and the SWM OR is the SWM/receiver side separated from the Dish/SWM side since the SWM is powered and creating its own stacks for each SWM channel?

    I know you would obviously still have potential signal loss to the receivers if you get rainfade, but if the Dish/SWM and SWM/receiver signals are not directly related you could have lower signals on the SWM/receiver runs that would not affect the susceptibility to rain fade or signal loss on the Dish/SWM side. Do you see what I mean? This would be a good thing as you could have a fair amount of loss in the runs between the SWM and Receivers that would not make a difference at all as far as your Dish signal strengths and ability to withstand rainfade.

    This is kinda hard to explain in text, so I hope you guys understand what I am asking/thinking.
     
  2. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    I think the best place to get answers such as the ones you are asking is here:

    http://www.swm8.com/swm-faq.php

    Between the FAQ and specifications area....you should be helped considerably.
     
  3. Grentz

    Grentz New Member

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    I have looked around there and there is nothing that hints at or really says anything about my question. I already know pretty much everything in the FAQs and Specs on that site already. As I said, I am not confused about installation, specs, anything like that. I am just curious about how it handles the signal...more of a technical question. I already know how to install it, use it, etc. and have already helped many get theirs setup around here.

    So no one else has any idea, or was my question not clear enough?
     
  4. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    Apparently not....:lol: :lol: :lol:

    Ok...lets try this... :D

    The FAQ section only mentions the following infomation pertaining to the impact of using a spliter on multiple runs (in terms of reducing signal levels): Hopefully, that addresses your question better. Apparently the overall coax run length of the total number of runs does have some impact to ALL the connected devices as a whole. As to if they are impacted differently,....no idea.

    "If you are connecting only one or two receivers to a SWM port (using no splitter or a 1x2 splitter), each can be as far as 300’ away from the SWM. If you are using a 1x4 splitter, the maximum distance is 250’. If you are using a 1x8 splitter, the maximum distance is 200’. Note that results may vary, and if you find that you are not getting a signal or that you are missing transponders or having other problems with particularly long runs, you might require additional equipment (such as an amplifier)."
     
  5. Grentz

    Grentz New Member

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    I saw that part, but I assumed it had more to do with the larger splitter loss as you move up in the number of outputs. For example, with OTA splitters, 2-way are usually around -3.5db on each output, 4-way around -7.5db, and 8-way around -11db. So thus you would need shorter runs on the splitter side to the receivers since more of the signal would be lost in the splitter.


    I will try and add more to my original question...What I am trying to get at is whether the signal strength between the SWM and Receivers impacts the actual satellite signal strength at all, or if the two are unrelated.

    To give an example say the dish/SWM gets a marginal signal of 60%. The receiver then connects to the SWM and gets a signal strength of 75% on the SWM channel.

    Pertaining to my question above, if the signal from SWM --> Receiver DOES directly impact the satellite signals you would have a total loss of 65% to your satellite signals. If the signal from SWM --> Receiver is separate, you would only have a satellite signal loss of 40% because the communications from the SWM--> Receiver do not hurt the Dish/SWM signal received.


    ---------------------------------------

    So I think I just reprhased my question ( :p ). Does the SWM amplify the satellite signals so that the SWM/Receiver side is always working out of a theoretical 100%, or does it pass the signals through and thus the loss on the SWM --> Receiver runs directly degrade your satellite strengths OR potentially is there any other reason that the SWM --> Receiver signal strengths degrade your satellite signal and thus contribute to faster rainfade.

    Sorry this is so confusing, hard to explain and like I said, I do not believe there is a text book answer posted anywhere on it (at least that I have seen). But, in my mind at least, we are here to test the technology and this is part of understanding a part of how it is operating (at least IMO).

    and thank you for your replies hdtvfan, I know you are just trying to help :)
     
  6. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    I think I know what you're getting at....

    The SWM8 does amplify the signal a bit in comparison between the level of what comes in compared to what is going out....there should be 0 degregation, rather, in my case, levels were actually higher a bit...even higher than when I replaced a WB68 multiswitch with the SWM in the first place.....the SWM out put was higher than the multiswitch output.

    Is that what you're seeking to find out?
     
  7. Grentz

    Grentz New Member

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    Yes I believe that is what I was getting at. I knew we would get there eventually ;)

    That is a good thing, since it frees up the SWM --> receiver wiring a bit more unlike when using just a regular multiswitch where it can directly impact signal strengths with any of the internal wiring you do. Obviously if you push the limits too much no matter what you will have issues, but at least this way you are working with a bit more of a smart device inbetween (the SWM) and have a bit more play with your internal vs. external wiring.
     
  8. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    Yup.

    I got a 1-3 point gain on most transponder levels when inserting the SWM as a replacement for the original Zinwell multiswitch.
     
  9. mikeinthekeys

    mikeinthekeys Godfather

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    FWIW, I replaced a WB68 multiswitch with the SWM8 and while I didn't record all the values I had top strengths of 100 on two transponders on sat 101 and my lowest signal was 78. Most were in the high 95+ range. This was identical with my initial direct hookup of the SWM8. So no increase there for me. No splitters were used or abused in this first trial arrangement.
     
  10. hdtvfan0001

    hdtvfan0001 Well-Known Member

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    I took screen shots of my levels before and after so I could compare - 1 to 3 numbers higher on most transponders, and even on the rest for all sats. I suspect line length and other environment items can affext actual results. In my case, I know that my Sonora Power Inserter located between my Dish and splitters into my 2 parallel SWM's helps stablize and slighlty amplifies the inbound signal a fraction in and of itself.
     

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