Results 1 to 9 of 9

Thread: AGC gone from 80 to 2, should I be worried.

  1. #1

    Title
    Forum Supporter
    Donated Member
    Join Date
    Jun 2010
    Location
    Norfolk, UK
    Posts
    591
    Thanks
    377
    Thanked 170 Times in 104 Posts

    AGC gone from 80 to 2, should I be worried.

    When I last had a problem with my setup, which turned out to be the skew, the AGC was around 80 (both before and after I adjusted the skew).

    A few days ago we lost the signal for about 30 seconds (wasn't raining, and rain doesn't usually affect it anyway unless it's a cloudburst), haven't lost it since.

    Looking at random channels over the past few days , the AGC is always the same, it's only 2% compared to the 80% it used to be at.

    Since I last fixed my skew problem until a few days ago, I hadn't bothered checking the signal strength as everything was working fine.

    Should I be worried with only 2% AGC (it's more that it used to be 80% that's made me query it), or should I simply put loosing the signal down to a fluke with the weather?

    My SNR is now also always 100%.

    (I am running vix 5.2.043, not the latest version)

    For example, here are two screenshots taken today

    screenshot_20191112122126.jpgscreenshot_20191112122607.jpg

    and here is a screenshot taken a few months ago

    unicable.PNG



    Many thanks

  2. #2

    Title
    Forum Supporter
    Donated Member
    Join Date
    Jun 2010
    Location
    Norfolk, UK
    Posts
    591
    Thanks
    377
    Thanked 170 Times in 104 Posts
    Just updated to ViX 5.3.009 and it's the same

  3. #3
    twol's Avatar
    Title
    Moderator
    Join Date
    Apr 2012
    Posts
    5,975
    Thanks
    776
    Thanked 2,095 Times in 1,597 Posts
    Which receiver is it????????????
    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)
    .......................> FBC & DVB-S2X into 90cm dish (27.5W) Opticum robust Unicable LNB
    AX HD61, Edision Osmio 4K+, Zgemma H9Combo, Octagon SF8008 using Legacy ports on multiswitches
    Zgemma H9 C/S into Giga4K

  4. #4

    Title
    Forum Supporter
    Donated Member
    Join Date
    Jun 2010
    Location
    Norfolk, UK
    Posts
    591
    Thanks
    377
    Thanked 170 Times in 104 Posts
    GiGaBlue HD-ULTRA-UE

  5. #5
    twol's Avatar
    Title
    Moderator
    Join Date
    Apr 2012
    Posts
    5,975
    Thanks
    776
    Thanked 2,095 Times in 1,597 Posts
    As long as you are receiving without issues, I wouldnt worry
    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)
    .......................> FBC & DVB-S2X into 90cm dish (27.5W) Opticum robust Unicable LNB
    AX HD61, Edision Osmio 4K+, Zgemma H9Combo, Octagon SF8008 using Legacy ports on multiswitches
    Zgemma H9 C/S into Giga4K

  6. The Following User Says Thank You to twol For This Useful Post:

    Ojustaboo (19-11-19)

  7. #6
    adm's Avatar
    Title
    Forum Supporter
    Donated Member
    Join Date
    Sep 2014
    Location
    Southend on Sea, UK
    Posts
    1,006
    Thanks
    36
    Thanked 377 Times in 297 Posts
    Quote Originally Posted by Ojustaboo View Post
    Just updated to ViX 5.3.009 and it's the same
    What is the AGC (Automatic Gain Control) figure actually indicating? Traditionally an AGC attempts to normalise the input to a fixed level for the following stages hence a high input and a low gain applied and conversly a low input and a high gain applied.
    If you have improved the level of your input signal then an AGC would apply a lower gain. This is perhaps what the AGC figure on the box is showing.
    Last edited by adm; 18-11-19 at 21:36.
    Xtrend ET10K, 2 x satellite tuners 28.2 (UK Freesat channels), 2 x hybrid (UK Freeview channels)

  8. The Following User Says Thank You to adm For This Useful Post:

    Ojustaboo (19-11-19)

  9. #7

    Title
    Forum Supporter
    Donated Member
    Join Date
    Jun 2020
    Posts
    110
    Thanks
    6
    Thanked 6 Times in 4 Posts
    Interesting. I'm now foreign with the same LNB, receiver, DC injector and splitter as a couple of days ago in UK.
    In UK 100 SNR, 2-4% AGC and 16.5 dB.
    In FR Tuner A is the same but Tuner B AGC has shot up to 100%.
    Nothing changed. Rebooted, no different.
    Strange??
    June 2020 - GigaBlue UHD Quad 4K, 2Tb internal HDD, OpenVix 5.0.35. GigaBlue Ultra SCR-LNB 24 SCR - 2 Legacy UHD 4K LNB. Inverto DC Power Injector. Splitter to feed both Tuners. 3 FBC channels of each tuner, total 8.

  10. #8
    adm's Avatar
    Title
    Forum Supporter
    Donated Member
    Join Date
    Sep 2014
    Location
    Southend on Sea, UK
    Posts
    1,006
    Thanks
    36
    Thanked 377 Times in 297 Posts
    Quote Originally Posted by CRMS View Post
    Interesting. I'm now foreign with the same LNB, receiver, DC injector and splitter as a couple of days ago in UK.
    In UK 100 SNR, 2-4% AGC and 16.5 dB.
    In FR Tuner A is the same but Tuner B AGC has shot up to 100%.
    Nothing changed.
    So you are using the same undisturbed cables from the LNB to the splitter and the same undisturbed cables from the splitter to your box?
    Badly made cable or F plug connection?
    F plugs not fully screwed home?
    Kink in the cable? Are you using a cable with foam dielectric that resists kinking better?

    Swap A and B over to see if the AGC values swap over.
    Have you got any unused outputs on any of your splitters? If so terminate them with a 75 ohm load.
    example
    Code:
    https://tinyurl.com/yyahgbqv
    Xtrend ET10K, 2 x satellite tuners 28.2 (UK Freesat channels), 2 x hybrid (UK Freeview channels)

  11. #9
    BrianTheTechieSnail
    Quote Originally Posted by adm View Post
    Have you got any unused outputs on any of your splitters? If so terminate them with a 75 ohm load.
    example
    Code:
    https://tinyurl.com/yyahgbqv
    But note that if there is power or 22kHz signalling on the unused port(s) you really need a 75 ohm load that presents 75 ohms at RF frequencies only, while being high impedance at DC or 22kHz.
    I'm afraid I have no idea if such loads are or are not easily available.

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.