433 & 900 MHz Radio for Subs

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  • Sodamaexchen
    Lieutenant, Junior Grade
    • Jan 2023
    • 11

    433 & 900 MHz Radio for Subs

    I do not know if this is known here but there is a alternative to the old radios using 72 /40/35 Mhz.


    In the drone communitiy there is a system called Express LRS which works on 900/868 or 433 MHz.

    for more info: https://www.expresslrs.org/3.0/

    its a plug in for all modern radios that run Opentx or Edge TX.

    This way you can use a computer radio and also get telemetry data back from the sub, depending on your setup.

    Here is more info about everything 433 /900 Mhz: https://www.theassociationofmodelsub...mhz-and-433mhz

    I tried this in my Alfa and i get similiar range on 868 Mhz as with my old 40 Mhz equipment.

  • JHapprich
    Captain
    • Oct 2017
    • 712

    #2
    Are we allowed to use those frequencies for boats and subs in GER?

    Schönes Wochenende!

    Gruß Jörg

    Comment

    • Sodamaexchen
      Lieutenant, Junior Grade
      • Jan 2023
      • 11

      #3
      Yes.
      433 and 868 is used for things like weather stations and Garage openers.
      Actually when setting up the eLRS, there is a selection for which regulatory area the system is used.

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      • neitosub
        Lieutenant Commander
        • Nov 2021
        • 129

        #4
        Do the 433/900mhz systems have standard 6ch+ receivers? Or do the receiving modules plug into something like a drone flight controller?

        Comment

        • Sinksalot
          Commander
          • Mar 2020
          • 332

          #5
          Please note, not all 900mhz radios have pumping power and signal sensitivity good for subs. So far the best I seen for both is the TBS crossfire 915mhz. Some expressLRS 915mhz are good too. The main problem for is these system were designed for long range drone flying and you need to solder a PWM Converter daughter board to a drone receiver to get 6 or 8 channels for servo use. There are some 10 channel board to. However TBS crossfire system has a prebuilt 8 channel 915 mhz receiver with 2 antennas.

          Click image for larger version

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          • Sodamaexchen
            Lieutenant, Junior Grade
            • Jan 2023
            • 11

            #6
            There is also a 6 Channel Receiver from Happy Model.
            they are small and have good range.

            https://www.happymodel.cn/index.php/...or-fixed-wing/

            I personally use one with a serial connection together with a flight controller. The FC is used as a stabilizer to keep the sub level.
            it also monitors battery voltage & current and thus is send back via telemetry to the radio.
            unfortunatly the telemetry signal is week and only transmits close to the surface.
            Last edited by Sodamaexchen; 01-14-2023, 04:56 PM.

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            • Sinksalot
              Commander
              • Mar 2020
              • 332

              #7
              They also sell a 8 channel that you solder together. The receiver goes on top of the daughter board and is solder on very easy as it fits like a glove. i both receivers you can add stabilizer or anything you want. I have both receivers for testing in subs. Also the antenna are smaller in this version. So far both receivers have passed the tests, just have a few more tests then I will make a video. The reason I like the prebuilt one is, there alot of older guys who run RC subs and soldering tiny things is a bit harder for them.

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              Last edited by Sinksalot; 01-14-2023, 12:44 PM.

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