Posts by 2E0TVA

    I tried dvb-s_gui_amsat and had good results with the wide band tv channel plus a couple of narrow band transmissions but most of the transmissions just will not decode.

    as a general rule are the transmissions all DVB=S2 or are some S1?

    and the various other settings do they need to be changed from the default? obviously the sym rate has to match the transmission but what about fft, bb gain, spectrum, rf filter, rrc taps etc?

    all the signals I tried look strong and I set the sym rate correctly output to vlc is tcp and carrier recovery is enabled just as with the working transmissions but no video on most.

    I ordered also from Amazon and became an other Opticum model, but the LSP-04H was OK. I think you received a "compatible" model with PLL. DRO type models are not on the market, except on flea markets, its an old technology.

    8kHz drift is normal after switch on. Does your DAXIS wobble ? That's much more important than drifting. Wobbling without a modification makes the LNB unusable.

    The Daxis LNB has no wobble at all and after being plugged in for 8 hours there is only a drift of about 800 Hz so much less than after 2 hours.

    maybe because the sun is not shining on the LNB in the evening so a cooler temperature is not so drifty?

    Anyway if the Opticum is no better I may as well keep this Daxis.

    Image shows drift over 4 mins on a slow waterfall.

    I ordered from Amazon the OPTICUM LSP-04H. LNB

    but for some reason this morning I received a DAXIS AS0420 LNB

    I just tested the Daxis and it drifts about 8KHz! I left it running for a few hours.

    There is no mention on the spec if its a DRO or PLL type, anyway its as bad as the old DRO LNBs which I already have.

    I will contact the Amazon seller to see why he sent a different LNB model

    If I manage to get hold of a OPTICUM how much drift should I expect?


    Technical characteristics: DAXIS AS0420 LNB

    • Input Frequency:
    • Low band: 10.70~11.70 GHz
    • High band: 11.70~12.75 GHz
    • Output Frequency:
    • Low band: 950 ~ 1950 MHz
    • High band: 1100 ~ 2150 MHz
    • Local Oscillator:
    • Low band: 9.75 GHz
    • High band: 10.60 GHz
    • Noise Figure: 0.1 dB (típ.)
    • Gain at 25ºC: 58 dB (min.) / 63 dB (máx.)
    • Gain stability: ± 0.5 dB / 26 MHz
    • Crossed Polarization Isolation: 25 dB (típ.)
    • Local Oscillator stability:
    • ±1.0 MHz (max.) @ +25º C
    • ± 2.0 MHz (max.) @ -40º C ~ +60º C
    • Phase noise of the local oscillator:
    • -50 dBc / Hz @ 1 kHz
    • -75 dBc / Hz @ 10 kHz
    • -95 dBc / Hz @ 100 kHz
    • Image Rejection: 40 dB (min.)
    • VSWR: 2 : 1 (tip.)
    • Current consumption: 70 mA (máx.)
    • Band Change:
    • Low Band: 0 kHz
    • High Band: 22 kHz ± 4 kHz
    • Voltage - polarization change:
    • 12.0 ~ 14.0 V Vertical
    • 16.0 ~ 20.0 V Horizontal
    • Operating Temperature: -40ºC ~ +60ºC

    I just googled your lnb. This model is for a multi switch, so only one of four outputs provides the polarisation and band you need. Did you take this into account?


    Hi, Yes as pointed out by SWL-jsilva to try the Vertical Low socket for the narrow band QO-100, in fact I tried all the sockets and came to the conclusion that this particular LNB doesn't get down to 739MHz, having tested many LNBs *DRO types* they all do cover 739 but drift a lot.

    The only PLL LNB I had in the shack was this particular Best model which I assumed would work too but not a peep from QO100.

    Anyway in a few days I should have a shiny new OPTICUM LSP-04H.

    Maybe the LNB uses some other multiplication factor, not 25MHz*390=9750. But anyway, once you found the signals from QO-100 around 874MHz, you can calculate your downconverter offset. 10489.8-874.4 =9615.4 . Now setup your transverter definition in sdr console using 9615.4 - not 9750 - and you are good to go. I beleive the 400kHz after the decimal point is the inaccuracy of the internal crystal, so the offset is either 9615 or 9616 . But i also might be totally wrong. The fact that both lnbs show signals at 874.4 may lead to the conclusion that this really is directly fed into the sdr , not via the lnb. 437,075*2=874,15 .

    73, martin

    It didnt work, 874,40 MHz was only the output from the walkie. not a peep out of QO-100

    Thanks for the tip anyway, it was interesting to try.

    Your "Super" LNB is unsuitable for QO-100 I think. There are many other LNB's on the market for little money. If you don't want to modify it, look for Opticum. They are not rock stable but have a clean signal.

    Martin described the procedure to test a LNB correct. Would this help you at the moment ? Otherwise tell us your requirements to an LNB.

    Thanks for the info, I was just trying to test what I had in the shack and learn along the way but the DRO LNBs are too drifty and yes the Best LNB just doesn't work.

    Can you confirm before I buy that the OPTICUM LTP 04H will receive QO-100?

    If not which of the OPTICUM LNBs will work?


    Exactly, you should receive a carrier on 10489.8 -9750 = 739.8MHz .

    If you already set up sdr-software like sdr-console or similar, you should see a needle coming out of the noise around that frequency.

    This ensures you that your lnb is working.

    73, Martin


    Testing the Universal DRO LNB which works OK with OS100

    input from walkie 437.075 MHz output 738.80 MHz and 874,40 MHz

    Testing the Best PLL LNB which does not work with OS100

    input from walkie 437.075 MHz, the output only shows at 874,40 MHz

    nothing at 738.80 MHz

    still its a mystery when using the Best LNB on LOW H why I can see 30 MHz wide transponders from 620 MHz to 900 MHz from BADR sat when they should start at over 950 MHz

    Exactly, you should receive a carrier on 10489.8 -9750 = 739.8MHz .

    If you already set up sdr-software like sdr-console or similar, you should see a needle coming out of the noise around that frequency.

    This ensures you that your lnb is working.

    73, Martin

    OK I see now, but I would need to be distant from the SDR otherwise the SDR would be just receiving the transmission directly if too close. Thanks


    You can try receive the 24th harmonic of 437.075 =10489.8 ( 739.8 if the crystal is 25MHz , or 1105,8 if 24MHz)

    Just transmit with your handheld in front of the lnb. Remember any frequency error from your handheld will be multiplied by 24. So you may have to search a bit for the signal depending on the overall accuracy.

    73, Martin

    Sorry I don't understand, do you mean if I transmit in to the LNB at 437.075 MHz I should see a signal at 10489.8 MHz less the LO of 9750 MHz?

    Many of the LNBs have just glue all around the edges of a plate and are very difficult to open (no screws)

    I know the DRO types well as they have 2 ceramic discs and often 2 screws above them for the final tuning at the factory.

    I will have another try with the Best LNB to check the noise floor at 10.489 GHz.

    Perhaps the first time I just missed the transponder because the V/H skew was off plus the extra complication of the 4 different output sockets.


    You should use the V Low for the Narrowband Transponder and H Low for the Wideband transponder, assuming you apply the correct skew for your location. If you mess the skew up by 90 degrees, you will need to swap the H/V connectors.

    We are kinda working out of spec since QO-100 downlinks outside the official supported range for common COTS LNBs. While most of them work on 10.489, one should not take for granted that every single LNB will work outside of the specified range.

    Thanks for the info, so maybe I just got unlucky and this particular LNB doesn't quite get down to 10.489 GHz

    I have many LNBs and all the ones I have tested so far tune down to 10.489 but they do drift.

    some of the LNBs I have are unmarked, is there any way of knowing if they are PLL type or not without opening them or mounting them on the dish and testing the signal for drift?, lots of them have glued backs without screws so its not easy to look inside. I did open one or two and they appear to be the DRO types. The Best HQDL 414 plus LNB was the only one I have which I thought was PLL as its marked crystal controlled.


    I have a Best HQDL 414 plus LNB which is apparently PLL to give better stability on reception , Im not 100% sure about the PLL but it does say "crystal controlled" on the LNB itself.

    The LNB has four F outputs marked (V High) (H High) (V low) (H low)

    When I tried to get a QO100 signals it did not work even though the dish is correctly aligned and works OK with a unmodified universal single output Lo 9.75 GHz LNB (except it drifts).

    I searched through the band with the Best LNB and can see the transponders of the Badr satellite so I know the LNB is working but I cannot find the amateur transponder. I tried all four sockets.

    Does anyone know which of the four outputs should be the correct one to use for QO100 reception?

    Any ideas what may be the problem? maybe this LNB is not compatible? even though it has the same input and output as the universal LNB 10.7 to 12.75 GHz

    And why does my unmodified universal LNB work anyway as supposedly it has an input starting at 10.7 GHz but QO100 is around 10.5 GHz?

    Best HQDL 414 plus LNB spec :

    Input : 10,7 - 11,7 GHz / 11,7 - 12,75 GHz

    * L.O. : 9,75 GHz / 10,6GHz

    * Output : 950-1950MHz / 1100 - 2150 MHz