Signal noise problem with AVerTV Volar hd2 USB DVB-T tuner

  • Hi,

    I have some signal noise problems using an USB DVB-T tuner AVerMedia AVerTV Volar hd2 (seen as Afatech AF9033 in TVHeadend).

    When I plug the antenna cable on my Sony TV, everything works fine. The signal information page gives a "Pre Viterbi" of about 2e-4.

    On the computer (HTPC), I sometimes have a lot of Transport Errors and Continuity Errors. The signal is usually very good, but several times per hour, it gets totally scrambled. When this is the case, it seems to me that stopping the client and starting it again solves the problem, which is weird.

    For instance, at this moment, the program I am recording has >100000 errors.

    The PER (Packet Error Ratio) is about 0.06, the SNR 31.5 dB and the signal strength -34 dB.

    At some other moments, everything works fine.

    I use LibreElec 9.2.3 with TvHeadend 4.3-1886 (nightly build).

    I have tried :

    • to enable/disble the LNA (low noise amplifier) in TvHeadend
    • to enable/disble "Force old status" in TvHeadend
    • to enable/disable the latest drivers in LibreElec
    • to play with the 167KHz offsets
    • to replace my cables, amplifier, HTPC

    but it did not improve this problem.

    Below are a few screenshots: in 3 of them everything works fine, but in the last one, the image is noisy.

    I also add a log of a buggy session:

    • I start the streaming at 14:16:44
    • It works fine until 14:44:14 when I encounter the first continuity errors
    • I stop it during the errors at 14:53:35 and start it again immediately
    • then it works fine during at least 15 minutes, though before stopping it, there were errors every minute

    Do you see anything I could try in order to understand why I get this high noise ?

    Should I try another USB tuner?

    Thanks

    yesterday

    force old status

    today

    signal noise example

  • did you tried an recent Nightly LE version, Kernel 5.7?

    It is very likely that the 5.1 Kernel has problems with that stick (maybe DVB related, maybe usb ...), everything else you tried (tvh board matrix) has an much older Kernel or the Ubuntu versions carrying massive kernel patches.

  • did you tried an recent Nightly LE version, Kernel 5.7?

    It is very likely that the 5.1 Kernel has problems with that stick (maybe DVB related, maybe usb ...), everything else you tried (tvh board matrix) has an much older Kernel or the Ubuntu versions carrying massive kernel patches.

    Hello,

    I just tried that, but this did not seem to improve the situation:


    Start time Hardware OS Kernel TV tuner DVB Module PVR Amplifier ?
    Amplifier level Cables Duration (s)
    Poor signal count (s) UCB (uncorrected blocks) First UCB at (s)
    06/08/20 17:52 HTPC LibreELEC-Generic.x86_64-9.80-nightly-20200804-a26fe97 5.7.6 AVerMedia AVerTV Volar hd2 dvb_usb_af9035 5.7.6 TVHeadend yes 50% pink+ blue 2500 93 58448 1208