sl3s + 21v pi + frequency sweep from 150mhz to 2150mhz

Discussion in 'DIRECTV General Discussion' started by tdbone1, Jan 21, 2019.

  1. Feb 1, 2019 #61 of 259
    dreadlk

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    Slice what I am talking about is what is the noise floor of the SDR unit itself. Not the SNR. If the unit itself has a -40dbm noise floor then any signal lower than that will be buried in the SDR's own internal noise and even signals that may be at -30dbm may be highly degraded. A fairly low end Rigol DSA815 SSA may have a noise floor of -100dbm which is good enough for most hobbyist testing. BTW the noise floor change on an SSA depending on the RBW you are using.

    As I stated above I am not sure what you are trying to achieve.
    If your just trying to see the different transponders and their center Freq and bandwidth then an SDR will do the job just fine. If your trying to decode some digital Data then that is a whole different ball game. BTW with the AIM meter the strongest signals I am seeing are -38db and the SNR is 17.6db
    The SQ is a solid 100.

    I am very interested in helping you if I knew more about what you are trying to achieve. It's kind of sad that I have the test gear to do a lot of this stuff but I have never really seen a purpose in looking further into it. Maybe you have an idea that might peak my interest. At one point I was thinking about looking for where the guide data is and I did locate the transponder but never went much further.
     
    Last edited: Feb 2, 2019
  2. Feb 2, 2019 #62 of 259
    slice1900

    slice1900 Well-Known Member

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    Ah OK a noise floor of -40 dbm would indeed be a problem.

    I'm not the one trying to do stuff with the SDR, I don't have one, nor a spectrum analyzer. The TS tdbone1 is the one trying to use it, apparently for radio astronomy using a Directv dish & LNB (which is IMHO impossible regardless of what other equipment one may have)
     
  3. Feb 2, 2019 #63 of 259
    P Smith

    P Smith Mr. FixAnything

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    Looks like TS/OP lost its interest in our discussion ...
     
  4. Feb 2, 2019 #64 of 259
    dreadlk

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    Sometimes something looks like it might be easy to do but then you find out that it's not so easy! In this case I think it's more of a lack of equipment as if you have an electronics background and the right equipment you can examine a lot of signal components.

    The problem for me is that my time is very short each day for personal activities and I just cannot see what I would do with the information even if I had it. Although I would love to see the Guide data stream just to see why it takes so many days for it to gather 2 weeks of guide data. It must be sent at modem speed :)
     
  5. Feb 3, 2019 #65 of 259
    P Smith

    P Smith Mr. FixAnything

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    It's matter for other [new] thread, if you do worry about DTV APG … but I'm assure you - it's not true. Ask Gary Toma ;)
     
  6. Feb 3, 2019 #66 of 259
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    Is it time to put a fork in this thread?
     
  7. Feb 3, 2019 #67 of 259
    P Smith

    P Smith Mr. FixAnything

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    nay ... OP/TS should say final words... we don't know how he satisfied by all the info posted here
     
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  8. Feb 5, 2019 #68 of 259
    dreadlk

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    It’s an interesting thread, why close it?
     
  9. Feb 5, 2019 #69 of 259
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    1) has little to do with DirecTV
    2) It seems to have run it's course
     
  10. Feb 7, 2019 #70 of 259
    tdbone1

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    ok cool guys. i back
    nope im still interested.
    had alot going on in the past week.
    im back and actually have everything hooked up right now and am already running qspectrumanalyzer.
    will try and explain what i would like to do with the dish and swim lnbf.
    anything i can :)
    i have been playing with rtl-sdr for a few years now.
    i got the limesdr-mini last year.
    i found this DirecTV Dish and SWiM SL3S LNBF and paid for an official directv 21v PI
    was trying to experiment with the different Local Oscillator's
    i know there is Ka-Low, Ka-High and Ku
    I believe i am stuck in Ku which is the center antenna on my lnbf horn
    i would like to be able to switch to Ka but i think im going to have to find older pre-swim or can i buy a directv recievers (IRD) and it have an extra output port that i can hook to my Limesdr-Mini?
    also my limesdr-mini does have a Tx
    i wish i knew more about this stuff i bet i could switch modes with command on that 38.4kbs channel
    if i can do that with a meter to put this lnbf in modes as far as Ka and Ku bands and polarities that would be awesome too
    i dont know. what do you suggest?
    i am at your disposal :)
    [​IMG]
     
    Last edited: Feb 7, 2019
  11. Feb 7, 2019 #71 of 259
    P Smith

    P Smith Mr. FixAnything

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    It's FSK at 2.3 MHz !
     
  12. Feb 7, 2019 #72 of 259
    tdbone1

    tdbone1 Member

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    i dont think this limesdr-mini can go that low.
     
  13. Feb 7, 2019 #73 of 259
    dreadlk

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    If your going to play with this stuff for scientific data I suggest not using a SWM LNB but using an older SL3 hooked to an older multiswitch rather than using SWM. It is very easy to separate out the different LNB's and their signals with an MS.

    As for Tx, I am not sure what you mean? I assume you want to Tx a signal to the SWM to make it change LNB's? You could simply do that by putting a splitter in the line and have a receiver send the signal to the SWM while you monitor the other side of the splitter with your SDR to see what transponders the SWM is sending to the receiver.
     
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  14. Feb 7, 2019 #74 of 259
    tdbone1

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    which transponder numbers correspond to which channels in alignment mode???
     
  15. Feb 7, 2019 #75 of 259
    slice1900

    slice1900 Well-Known Member

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    I don't know. And I don't understand why you keep fighting this stupid SWM LNB. Get a legacy LNB!!!!!!
     
  16. Feb 7, 2019 #76 of 259
    P Smith

    P Smith Mr. FixAnything

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    nobody knows that !!!
     
  17. Feb 7, 2019 #77 of 259
    tdbone1

    tdbone1 Member

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    probably because this sl3s is all i have
    you guys said you thought i had given up recently. i said i didnt. now am i supposed to say yes?
     
  18. Feb 7, 2019 #78 of 259
    veryoldschool

    veryoldschool Lifetime Achiever Staff Member Super Moderator DBSTalk Club

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    After someone understands post #58, the next issue will be why DirecTV parts are so cheap: NOISE isn't their problem.
     
  19. Feb 7, 2019 #79 of 259
    James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

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    The consensus is that you need something better. A simple legacy LNB is better. You can fight the sl3s until you are frustrated or figure it out for yourself or you can get a cheap easier to use LNB.

    The "give up" comment was because the thread was continuing - deep in discussion - without you. I'm glad you're back.
     
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  20. Feb 7, 2019 #80 of 259
    tdbone1

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    guess i will be looking for some older tech then SWiM enabled devices
    is there any hardware mods i can do to this sl3s lnbf before i call it quits?
     
    Last edited: Feb 7, 2019

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