HomeElectronicsG-OSD mod – new input


G-OSD mod – new input — 8 Comments

  1. Hi Majek!
    Thanks for your article and schematics!
    I figure you have some understanding on how this G-OSD works… Perhaps you could help me with my problem: my video goes BW when I connect my camera to OSD. It does flicker BW/Color but stays BW most of the time…
    The camera alone does give a clean color image. Any ideas what I could do?
    Thanks for your time,

    • Hello Dmitry

      Did you checked your connections for ground loop? If you connect ground in wrong way, a weird things happen (up to video signal loss). G-OSD itself shouldn’t influence colour – in fact it makes modifications to video signal only where characters are – other parts of signal is untouched. Try to rewire connections and check if it helps. I had similar problem (poor colour and sometimes synchronization lost) and I solved it by disconnecting redundant ground wires.
      If you power video from the same battery as motor, I’m pretty sure you have at least two grounds connected to the osd – one on video side, second from battery and it forms a loop with ground for powering video TX. Leave only one ground connected to OSD and it should help.
      Or try to test this with separate battery for video equipment.

      • Hey Majek!

        Thanks for your reply!
        I was thinking about thiese ground issues as-well, but the strange thing is that I have a second G-OSDII (bought both at once -> should be the same batch), that works just fine with the same cable!
        Ok, but I get your point… I will try to re-solder the elements on the board – perhaps some cold-joint issue…
        (By the way, I accidentally broke a Quartz leg – do you know the specs exactly? Apart from it being 24Mhz)

        • I don’t think that it could be cold-joint. Your signal is weaker, so maybe R11/C8 have bad values. Or there is some short-circuit somewhere.
          Do you have proper OSD graphics?
          Regarding quartz – any 24MHz should work but I think that there will be hard to buy in such small package – standard HC49 should be no problem.

          • Hey, perhaps we should switch to email conversation, you should have mine, since it is necessary to enter prior sending this reply…
            Today I got the same effect with the second OSD :(.
            I got an impression, that new heat-shrink might be the reason for that (well, not the shrink itself, but the process of putting it ;)… Or that it is physically rather close to my VTx…
            I think OSD text is clean, it is hard to tell though…
            Will check the R11/C8 chain and short circuits…
            Thanks again,

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