DM 920 tuner...what a mess !!

  • Hello friends,
    have since two weeks this last receiver from DM that replaced an old 7080 and a VU+ Solo 4k..
    well well have a dish 80cm with a quad lnb pointing Hotbird and oh boys...on average I lost about 20% on a lot of
    channels looking back at the 7080 or the VU+ (on many channels where I had a 75% signal on
    the 7080 or the VU+, now I have 55-60% on the 920)...some channels are even more not watchable pixelizing and no signal...
    and this with the original twin sat dvb-s2 tuner and even with a brand new twin dvb-s2 multistream one in replacement...
    It's good to mention that I have also a dvb-t2 tuner in the other slot mounted...
    Don't inow what else to try among other things...tried different img, original unstable Dream Multimedia, OpenATV, DreamElite, and other
    SatLodge...even tried new dvb drivers...but nothing still the problem remain.
    Please if you know about it or a known issue let me know.
    Unfortunately I don't speak/understand german...just few school days words but no please in english.


  • mmm... should I suppose then that my 920 need technical (warranty) support? Because if it's not an issue I don't see what else to do...
    Look I'll try even to eliminate the DVB-T2 tuner and see if it get better... othewise I'll send it back to the reseller...


    PS;: I saw different topics here around im German concerning the 920 and tuner FBS and other thing... but again I don't understand quite well german...

  • I face the same problem with DM525 & till now I haven't any answer from dream multimedia to describe why this happen with the new DreamBox's ... also many posts for the same problem in many sites & there is No real answer to fix the problem or to show is this from hardware or software ... see my post ( Post 14 & 16 ) I'm sure that 100% your problem is the same with my problem ... Regards

    Need information about 525HD

    Edited once, last by samipeace ().

  • samipeace: No. There are no similarities between the DM52x and the Silabs based tuner modules.
    The tuner in DM520/DM525 is totally different to the Silabs tuner modules.

    The DM52x have an in SOC tuner... it is included in the main Broadcom STB Chip... (BCM73625)

    The Silabs Tuners are external Hardware...


  • Thanks Ghost for replay ..

    I know that they are totally different to the Silabs tuner modules ... I mean the same problem with the poor signal & AGC in many frequencies ... noting that when I use old model of DB all channels and frequencies are good ... ?(


  • all right dear friend Ghost,
    I made another two or three tries... the Si2169X (regular and multistream) that I
    have seem to get the same issues, as described, on the 920 and the old 7080 (about 20-25% signal lost)... I stick and try
    an old Alps tuner from a DM800 and boom... works like a charm, full signal on every channel no pixel... great... but can't keep on use the Alps because it's a in-out only tuner.
    So maybe I get to the conclusion that the Si2169X have kind bad relation with my
    brand new lnb, a Inverto Black Ultra quad, or maybe the software have to grow to include such lnb in the kernel... I don't know... receiver is ok.

    If you have advices about.... welcome


    PS: another weird thing is that on lnb1 on Si2169X tuners I loose more signal than on lnb2 in... about 5-10%...

    Edited once, last by scapin ().

  • what means 20% signal lost - the signal strength is logarithmic and calculated driver dependant, this is NOT a calibrated measurement device. Therefore any comparison of these values between diferent tuners with different drivers is ... useles ...

    If you want it takes DP less than 5 min to change the code to always report 20% better signal strength back from the new drivers, BUT this would also be as "correct" as the value of the old drivers.

    And showing/calculating % of a log scale is also nonsense BTW, because there is no 100% on a log scale.

    And quald LNB which get their operating current from the receiver are always a bad idea if you want optimal reception ... a Multiswtitch Matrix with their own power supply and a quatro LNB is then always the bebter choice.

    PS: Try increase currency in the extended LNB setings - some quad LNBs are suckers.

    Edited 2 times, last by Lost in Translation ().

  • ...sorry maybe I badly express myself...I meant that on a Vu I have 75% strengh on a channel and 50% on the 920 same channel and with the Si2169X tuner...
    About the current increase...already tested, nothing new...


  • Read again and try to understand what I wrote about comparing such values between different boxes, tuners and drivers and what percentage means for a logarithmic scale.

    Align your dish better, because I have 80- 85% on Hotbird with a small T55 wavefrontier and the same tuners and same box as you mentioned, but if course I sit in the center area of that beam.

  • I can confirm your issue.

    Tuner A1: BCM45308X (DVB-S2)
    Tuner B1: Si2169D (DVB-S2 / DVB-C / DVB-T2)
    Tuner B2: Si2169D (DVB-S2 / DVB-C / DVB-T2)

    With A1 i have 1.5 - 2,5 dB C/N more than with Si2169D. I crosschecked with a SPAROS-777-TOUCH - similar values as the Tuner A1.

    What happens if u use only one tuner? I remember my VU+ with 2 dual tuners. The second tuner had also less dB then the first one.



    PS: How the 2 tuners work in bad weather i can't say ... have the box and tuners since one week....

  • Sorry, you have no clue what you are talking about, don't compare different HW components.
    And the "SNR values" of the tuners are the MER not C/N0. The SiLabs demods are the most sensible components currently known.

  • Very Interesting!!! I was considering this box as an alternative to a Vu+Uno4K SE of which two I have tried and are NOT fit for purpose. The first one "BRICKED" on startup and the other after hours of setting up, crashed and became unusable. The common factor with your experience is the inability of the Vu+ Box to find many channels freely available using my old "Spider Box". The signal strength indicator was virtually useless but is seemed to indicate the box was very insensitive which coincides with you experience. Is there a common thread to this is issue?? One has to wonder when I had the proof right in front of me when testing the new box side by side with the "Spider Box" using exactly the same set up. I am really stuck as to what way to turn as I really am fed up returning items that should work and don't!! Perhaps someone with first hand experience might like to suggest something they use that is up to date but they know works really well??

  • I have a 920 UHD, with 2 SI tuners ( single lnb ) and 1 BMC. ( unicable, advanced, from diseqc )

    In the beginning I had a lot of trouble with reception, and recording. Especcially, because I also compared the performance with a 7080.

    By accident I changed the order of the tuners in the configuration, and at once the box functioned, as I was used to with my other Dreamboxes..

    I have no explanation, but my advice is, keep on trying different configurations.

    For the not-very-experienced Dreambox owner, with bad reception, I agree with earlier advice: check dish for optimal reception, and the connections of your