OBS Studio + PLUTO SDR TX DATV howto?

    My Bison ex-UMTS amplifier, I believe, is run in class AB and typical bias is around 0.7 to 0.9 for each device.

    A point to check, did you update to the official PlutoSDR 0.31 firmware before going for the F5OEO firmware?

    If you can run the Portsdown/Lime_Mini through the amp without shoulders then I would not be blaming the amp as the Pluto would just be acting as another source!


    Adrian

    Quote from G0MJW

    You can send the audio and video to ffmpeg running on your PC and then forward the TS as UDP to the Pluto. That TS can contain anything you want.

    All no problem, if one knows how ;)


    In the meantime i managed to send an UDP stream, as Robert described, to my Pluto. Unfortunately i couldn't get a software encoder for H.265 in OBS, so i stuck to H.264, which leads to a stuttering audio with 32kbit/s. ;(

    But the audio bitrate can not be lower than 32kBit/s (no downscale option at the Pluto controller page)...

    Well, I could localize the problem.

    It was my external 40 MHz TCXO into the Pluto. I changed to OCXO - the result was very very bad!!

    Then I tried my Bednar GPSDO - beautiful signal with -50 dB shoulders. That's the way to go.

    Unfortunatly I had used this GPSDO for my LNB and when I changed the LO for the LNB now to an external 24 MHz TCXO, the stability of the LNB went bad.

    So next days will try another method or get a second GPSDO.

    Has anyone changed the TCXO inside the Pluto and had similar problems regarding the shoulders?

    @OE3GBB


    Like the LNB, the Pluto can also be operated with an external 25-MHz clock.

    It is not necessary to recompile the firmware.

    The applied clock frequency must simply be transferred to the Pluto with the following commands:


    fw_setenv ad936x_ext_refclk "<25000000>"

    fw_setenv xo_correction 25000000

    pluto_reboot reset


    This is worth a try.

    Yes - I think this is really worth emphasising. You can use an external LO and it does not have to be 40 MHz. I saw someone designed a PCB for external input that does the switching so that the internal TCXO operates unless an external reference is present. This seems an ideal solution.

    Quote from OE3GBB

    Next problem: Is it possible, that the Pluto with the beta firmware from F5OEO doesn't operate in TX with SDR-Console any more? RX is OK, but no output signal.

    Dear OE3GGB,


    I had the same issue solved updating SDR console to the last version.


    Try and if you will have problem, try also to delete the Pluto in the SDR window and insert it again.


    Hope it's useful.


    73

    btw...

    can anyone tell me how the correct syntax for frequency correction look like in the config.txt on Pluto?


    [SYSTEM]

    xo_correction =


    And, what does this value mean?


    correction factor (to multiply by 40) ? or frequency offset (in Hz, kHz, MHz) or whatever?


    Robert

    DD4YR


    Hi, Robert,


    you are right, the term "xo_correction" is a bit misleading.

    You just have to enter the true clock frequency in Hz. For example:


    [SYSTEM]

    xo_correction = 40000123


    But if this value differs from the nominal clock frequency (e.g. 40.0 MHz) by more than 200 ppm, the Pluto will ignore it.

    Instead of editing the config.txt directly, you can also type in


    fw_setenv xo_correction 40000123

    pluto_reboot reset


    via console. In any case, the correction is not applied until a reboot.


    Roland

    Quote from pe1sde

    How can i put a roll off of 20 in the script in

    The new firmware i can put fec sr but i dont read about the rolloff please help me ?

    That seems to be correct at present, with tests done for myself, I saw very little changes at the lower SR rates, but when you get to 1MS the settings kick in. The shape of the signal would get steeper sides. I think the best I could get was a roll off of 25, It could be down to a few things such as the modulator in the Pluto or to a feature to be worked on in firmware.


    I tend to set 0.25 roll off and let the Pluto do it's work. Looking forward to the next revision, but also consider this is not commercial software so it could take time as I am sure that Evariste will have more pressing matters.


    Adrian

    Hello All,
    in the meantime I got a second Pluto and I also finished my 250W PA with BLC2425M9LS250.
    But there is a new problem with OBS now. I have used UDP-recording to port 8282 of the Pluto before with success and had fine DATV transmissions in H265 over the satellite with my 100W SSB PA in RB modes.
    But now, even I can see the stream working into the Pluto (Analyse mode), when receiving directly on 13cm with Minitioune I see H265 but no video, although I get the audio decoded.
    I then changed the udp stream directly to VLC (32bit) on the same PC and got the same - no video but audio.
    I also tried different resolutions, SR and FEC. I am using the basic - profile from BATC for OBS.
    Any ideas I could try to get the video working again?
    Gerhard