How deep can you dive and still maintain signal?

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  • Nicoolai
    Ensign
    • Jul 2019
    • 6

    How deep can you dive and still maintain signal?

    Hi,
    I'm a total noob, actually more like the step before newbie.

    I'm playing around with the idea of building a sub and I was wondering, what kind of depths can you realistically dive to, and still maintain signal connection?
    I already have a 2.4ghz system (which is pretty common here) but is it better to use something else, for subs?
  • trout
    Admiral
    • Jul 2011
    • 3545

    #2
    Welcome, at some point we were all newbies. The common question asked is how deep can you go? The answer is all the way to the bottom! You did put a qualifier in there, realistically and maintain signal connection. So, we can skip the common answer. With 2.4GHz you can dive, but your antenna must stay above water. It is used by some already and most of the time we run at periscope depth. Water and 2.4GHz are not compatible for diving any depth because it gets (to keep it simple) absorbed by the water. We typically run in the sub-GHz range like 75MHz in the U.S. and 40MHz in other countries (I do not know where you live).
    Even using a legal frequency, we typically do not dive more than 3 feet or less (but some run their sub 20' down). Why? To maintain visual contact. When you build your sub and sink in $$, you want to protect your investment. In super clear water you can gain confidence to go deeper, but in muddy or cloudy water, you cannot safely run blind. Before you ask about FPV, remember about 2.4GHz? You need an antenna above water or a cable all the way to shore to get live video feedback. Good first questions.
    Last edited by trout; 07-30-2019, 08:57 AM.
    If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

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    • He Who Shall Not Be Named
      Moderator
      • Aug 2008
      • 12253

      #3
      As to depth: If you can't see it, you can't drive it. You gotta be in the control-loop.

      As to FPV. I've done it, but as Tom points out, the camera transmitters antenna has to be above water.





















      And some video saved to Youtube: https://youtu.be/CxfA5d2L0BA (07:05)

      David
      Who is John Galt?

      Comment

      • STARK
        Lieutenant, Junior Grade
        • Nov 2009
        • 243

        #4
        What I Like to Know is Who Called the Ghostbusters?

        What one Man can do, YOU can do too!

        Comment

        • He Who Shall Not Be Named
          Moderator
          • Aug 2008
          • 12253

          #5
          Originally posted by STARK
          What I Like to Know is Who Called the Ghostbusters?

          **** you, Brian!

          Who is John Galt?

          Comment

          • trout
            Admiral
            • Jul 2011
            • 3545

            #6
            Bwaaahahaha! (spraying coffee all over my office!)
            If you can cut, drill, saw, hit things and swear a lot, you're well on the way to building a working model sub.

            Comment

            • Nicoolai
              Ensign
              • Jul 2019
              • 6

              #7
              Thank you guys, for your answers. That clarifies a lot.
              I was actually hoping to be able to FPV (some time in the far future). I guess I'll need to think a bit more about how to do that :P

              I live in Denmark. As far as I know, we can also use 40MHz but I'm pretty sure we're only allowed to transfer video over 2.4GHz :(

              Comment

              • DMTNT
                Commander
                • Jun 2018
                • 297

                #8
                Originally posted by STARK
                What I Like to Know is Who Called the Ghostbusters?

                If this photo were the last I were to ever see of DM-III, I could die a happy man....

                This isn't you, is it David? I'm assuming it's a real photo, and if not, that you probably know who it is.

                Dead men tell no tales...

                Comment

                • He Who Shall Not Be Named
                  Moderator
                  • Aug 2008
                  • 12253

                  #9
                  Originally posted by DMTNT

                  If this photo were the last I were to ever see of DM-III, I could die a happy man....

                  This isn't you, is it David? I'm assuming it's a real photo, and if not, that you probably know who it is.

                  That is the great Greg Sharpe. A fantastic model builder and one of the key innovators in this game. And that SCUBA shot is the real deal, that's him tooling around with his scratch-built 1/72 ALFA (which is the genesis of the Thor kit we all know and love). Greg and his fellow r/c sub builder-driver Dan Kachur, are the big movers and shakers up there in the great squid infested winterlands.

                  David
                  Who is John Galt?

                  Comment

                  • STARK
                    Lieutenant, Junior Grade
                    • Nov 2009
                    • 243

                    #10
                    Yeah, I remember his Water Tight Radio Box he is Holding and the Best Sheet Plans around. Dan Kachur, now there's is a Talent!!! Manta Sub was Dan's line, I bought the Sturgeon Hull Masters from Dan to make the 1/72 Sturgeon model I'm doing now.
                    What one Man can do, YOU can do too!

                    Comment

                    • DMTNT
                      Commander
                      • Jun 2018
                      • 297

                      #11
                      Originally posted by He Who Shall Not Be Named

                      That is the great Greg Sharpe. A fantastic model builder and one of the key innovators in this game. And that SCUBA shot is the real deal, that's him tooling around with his scratch-built 1/72 ALFA (which is the genesis of the Thor kit we all know and love). Greg and his fellow r/c sub builder-driver Dan Kachur, are the big movers and shakers up there in the great squid infested winterlands.

                      David
                      The personalities of this hobby, combined with their incredible talent and creativity never cease to amaze me. Thanks for the cool backstory on that photo!
                      Dead men tell no tales...

                      Comment

                      • scubaed1911
                        Lieutenant, Junior Grade
                        • Jul 2019
                        • 45

                        #12
                        Great question Nicoolai!

                        I'm a noob too, and thanks also for the great responses and sharing!

                        Best,

                        Ed
                        If you're part of the particulate, then you're not part of the solution"

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