Page 1 of 3 123 LastLast
Results 1 to 15 of 45
  1. #1
    Forum Supporter
    Donated Member


    Join Date
    Dec 2014
    Posts
    168
    Thanks
    31
    Thanked 9 Times in 7 Posts

    Signal Quality Values

    It will probably not be obvious to most people that as of OpenVix 5.2.22, the problem of 100% signal quality reports present on most if not all tuner types should have been fixed. In particular using Signal Finder on the "Tuner config" menu page, and NOT forcing legacy stats on the "Tuner setup" pages :

    * The dB figure should not be much below ~20 dB when lock is achieved, nor much above ~50 dB (precise figures will depend on whether satellite, cable, or terrestrial).

    *The % figure should only be 100% for dB figures >= 42/62/50 dB for satellite/cable/terrestrial i.e. close to a main transmitter in the case of terrestrial.

    * Results from different tuner models should agree within a few dB.

    If these criteria are not met there would appear to be a remaining problem, probably specific to that tuner type. I am aware of a problem with one SundTek model, but are there others?

    Please note that the ABM DVB-T Frequency Finder and the Terrestrial Scan plug-in use the % figure to identify the best signal when receiving from more than one transmitter - if this is always the same value then the first found rather than necessarily the best will be chosen.
    Xtrend Xt10000 with 3 Freeview tuners

  2. The Following User Says Thank You to EMJB For This Useful Post:

    ccs (02-02-19)

  3. #2
    Forum Supporter
    Donated Member


    Join Date
    Sep 2014
    Posts
    2,419
    Thanks
    210
    Thanked 527 Times in 462 Posts
    This is what I see with a Sundtek MediaTV Digital Home USB Tuner Cable / Terrestrial HD (DVB-C/T/T2)

    The only value which changes is BER

    Code:
      <?xml version="1.0" encoding="UTF-8" ?> 
    - <e2frontendstatus>
      <e2snrdb>100 dB</e2snrdb> 
      <e2snr>100 %</e2snr> 
      <e2ber>0</e2ber> 
      <e2acg>100 %</e2acg> 
      </e2frontendstatus>
    Attached Images Attached Images

  4. #3
    Moderator abu baniaz's Avatar

    Join Date
    Sep 2010
    Location
    East London
    Posts
    18,530
    Thanks
    4,867
    Thanked 7,199 Times in 4,868 Posts
    I am not getting the constant 100%. Am I doing something differently to what I should be?
    Attached Images Attached Images

  5. The Following User Says Thank You to abu baniaz For This Useful Post:

    Sicilian (03-02-19)

  6. #4
    The Boss Sicilian's Avatar

    Join Date
    Mar 2010
    Posts
    28,394
    Thanks
    22,422
    Thanked 25,114 Times in 7,210 Posts
    Quote Originally Posted by EMJB View Post

    * Results from different tuner models should agree within a few dB.
    Your right in theory they should, but in practice they don't. I seen variances of up to 30-40% signal from boxes connected to same dish or terrestrial feeds.

    My bet is if you test the same boxes on other 3rd party images you'll get the same results, therefore you are welcome to ask the manufacturers to fix their drivers for whatever box you have.
    D I S C L A I M E R

    My right to post information is protected under the rights for freedom act. In all instances, information discussed here on my posts are either hypothetical in nature, out of general curiosity, common knowledge, public knowledge, or role-play. Any use of the collective descriptions and shared knowledge from any of my posts are at the sole discretion of the reader. I am not responsible for what you do with it!

    Follow us on Twitter 0penViX
    Rules can be found
    HERE
    Support our sponsor World-Of-Satellite
    HERE
    GIGABLUE UHD QUAD 4K, GIGABLUE UHD UE 4K, MUTANT HD51, VU+ ULTIMO 4K
    Triax 1.1m Powered by TM2600, Technomate 80cm Powered by TM-2600 and Fixed 28.2 Zone 2 dish





  7. #5
    The Boss Sicilian's Avatar

    Join Date
    Mar 2010
    Posts
    28,394
    Thanks
    22,422
    Thanked 25,114 Times in 7,210 Posts
    Also see attached
    Attached Images Attached Images
    D I S C L A I M E R

    My right to post information is protected under the rights for freedom act. In all instances, information discussed here on my posts are either hypothetical in nature, out of general curiosity, common knowledge, public knowledge, or role-play. Any use of the collective descriptions and shared knowledge from any of my posts are at the sole discretion of the reader. I am not responsible for what you do with it!

    Follow us on Twitter 0penViX
    Rules can be found
    HERE
    Support our sponsor World-Of-Satellite
    HERE
    GIGABLUE UHD QUAD 4K, GIGABLUE UHD UE 4K, MUTANT HD51, VU+ ULTIMO 4K
    Triax 1.1m Powered by TM2600, Technomate 80cm Powered by TM-2600 and Fixed 28.2 Zone 2 dish





  8. #6
    Forum Supporter
    Donated Member


    Join Date
    Sep 2014
    Posts
    2,419
    Thanks
    210
    Thanked 527 Times in 462 Posts
    Quote Originally Posted by abu baniaz View Post
    I am not getting the constant 100%. Am I doing something differently to what I should be?
    For me, Com6, C60- (785.8MHz) drops to zero signal quality when it rains, I'll check the sundtek tuner again when the signal starts to deteriorate.

    No other mux's are ever affected.

    Maybe I should have said in my previous post that there are no dB levels, just %'s, which is odd.
    Last edited by ccs; 03-02-19 at 11:10.

  9. #7
    Forum Supporter
    Donated Member


    Join Date
    Dec 2014
    Posts
    168
    Thanks
    31
    Thanked 9 Times in 7 Posts
    Quote Originally Posted by Sicilian View Post
    Your right in theory they should, but in practice they don't. I seen variances of up to 30-40% signal from boxes connected to same dish or terrestrial feeds.

    My bet is if you test the same boxes on other 3rd party images you'll get the same results, therefore you are welcome to ask the manufacturers to fix their drivers for whatever box you have.
    With the old API the term point at which SNR was measured was ill defined leading to discrepancies in what was being measured, but with the new API the definition looks fairly watertight. Another complication is that the frontend.c code for the old API has lots of correction factors for some tuners, and none for others which may reflect the fact that no-one has bothered to make the corrections rather than them not being needed. Were your 30-40% variations seen with tuners using the latest API?

    Incidentally, I assume your percentages apply to the dB values i.e. around 10-15 dB - a 40% variation in (linear) power is less than 2dB.


    EMJB
    Xtrend Xt10000 with 3 Freeview tuners

  10. #8
    Forum Supporter
    Donated Member


    Join Date
    Dec 2014
    Posts
    168
    Thanks
    31
    Thanked 9 Times in 7 Posts
    Quote Originally Posted by abu baniaz View Post
    I am not getting the constant 100%. Am I doing something differently to what I should be?
    Something looks very strange with the screenshots you have posted - the AGC and SNR % figures are always identical - it looks as if the wrong data is being displayed for one or other or both. The skin you are using does not display the SNR in dB terms, which is unfortunate as the percentage is derived from the dB figure by applying an estimated upper limit so the dB figure gives more information than the % figure. I find using the WebIf "/web/signal?AGC=" command on your browser to be accurate and reliable, though tuner selection is less convenient.

    Incidentally the reported type for your tuner is slightly different from that of ccs, which I believe is "Sundtek DVB-C (III) (1/0) (USB) (DVB-T2)", which might explain the differences in behaviour.


    EMJB
    Xtrend Xt10000 with 3 Freeview tuners

  11. #9
    Forum Supporter
    Donated Member


    Join Date
    Dec 2014
    Posts
    168
    Thanks
    31
    Thanked 9 Times in 7 Posts
    Quote Originally Posted by ccs View Post
    Maybe I should have said in my previous post that there are no dB levels, just %'s, which is odd.
    It is the skin you are using - compare the screenshots I sent you recently with Abu's above.
    Xtrend Xt10000 with 3 Freeview tuners

  12. #10
    Forum Supporter
    Donated Member
    adm's Avatar

    Join Date
    Sep 2014
    Location
    Southend on Sea, UK
    Posts
    794
    Thanks
    25
    Thanked 280 Times in 224 Posts
    Quote Originally Posted by EMJB View Post
    It is the skin you are using - compare the screenshots I sent you recently with Abu's above.
    Could the lack of a db reading be.......

    Menu -> Setup ;> User Interface -> Swap SNR in % with SNR in dB = yes/no
    Xtrend ET10K, 2 x satellite tuners 28.2 (UK Freesat channels), 2 x hybrid (UK Freeview channels)

  13. #11
    Forum Supporter
    Donated Member


    Join Date
    Sep 2014
    Posts
    2,419
    Thanks
    210
    Thanked 527 Times in 462 Posts
    Quote Originally Posted by adm View Post
    Could the lack of a db reading be.......

    Menu -> Setup ;> User Interface -> Swap SNR in % with SNR in dB = yes/no
    I've got it set to no.

    On my Si2169 tuners I see %'s on the top line, and dB below left, setting to yes swaps these round, but the Sundtek remains unchanged.

  14. #12
    ViX Beta Tester twol's Avatar

    Join Date
    Apr 2012
    Posts
    4,550
    Thanks
    568
    Thanked 1,446 Times in 1,129 Posts
    I think it depends on skin & whether your tuner is in lib/dvb/frontend.cpp and conversion factors are in place.
    Gigablue Quad 4K & UE 4K
    .........FBC Tuners:
    ------------------> DUR-Line DCR 5-1-8-L4 Multiswitch to 1.5M dish(28.2E)
    ------------------> Spaun SUS 5581/33 NFA Multiswitch to 80 cm dish(19.2E)
    Edision Osmio 4K using Legacy ports on multiswitches
    Octagon SF8008 DVB-S2X tuner using Legacy ports on multiswitches
    Zgemma H9 using Legacy ports on multiswitches
    Dinobot Mini 4K (C/S) into Giga 4K.

  15. #13
    Forum Supporter
    Donated Member


    Join Date
    Sep 2014
    Posts
    2,419
    Thanks
    210
    Thanked 527 Times in 462 Posts
    Well it started to rain much sooner than expected, and I'm seeing reduced snr levels, as I'd expect (well, hoped that it would match the signal level indicator on the tv as soon as it dropped ever so slightly).

    No dB levels, I guess this is a SundTek issue - I can't see how a skin will help, I've tried Vix-night-hd and Simple_1080 - any others??

    Any ideas why just one mux would be so sensitive to local rain - new aerial, new cabling, new variable gain signal booster/splitter, tree branches reduced significantly.
    Attached Images Attached Images

  16. #14
    Forum Supporter
    Donated Member
    adm's Avatar

    Join Date
    Sep 2014
    Location
    Southend on Sea, UK
    Posts
    794
    Thanks
    25
    Thanked 280 Times in 224 Posts
    Quote Originally Posted by ccs View Post

    Any ideas why just one mux would be so sensitive to local rain - new aerial, new cabling, new variable gain signal booster/splitter, tree branches reduced significantly.
    Roof or loft mounted aerial?
    Xtrend ET10K, 2 x satellite tuners 28.2 (UK Freesat channels), 2 x hybrid (UK Freeview channels)

  17. #15
    Forum Supporter
    Donated Member


    Join Date
    Sep 2014
    Posts
    2,419
    Thanks
    210
    Thanked 527 Times in 462 Posts
    Quote Originally Posted by adm View Post
    Roof or loft mounted aerial?
    Roof - the rain only lasted for an hour, and soon after Com6, C60- (785.8MHz) was back to normal.

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
This website uses cookies
We use cookies to store session information to facilitate remembering your login information, to allow you to save website preferences, to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.