RFD900, RFD900+ - New long range radio modem

Hi All,

I would like to introduce you to a new radio modem that we developed for very long range datalinks!


Some of the key features of the RFD900 are as follows:

  • Multi point and point to point link capability.
  • Long range >40km depending on antennas and GCS setup.
  • 2 x RP-SMA RF connectors, diversity switched.
  • 1 Watt (+30dBm) transmit power.
  • Transmit low pass filter.
  • > 20dB Low noise amplifier.
  • RX SAW filter.
  • Passive front end band pass filter.
  • Open source firmware / tools, field upgradeable, easy to configure.
  • Small (30 x 57 x 13 mm), light weight (14.5g).
  • Compatible with 3DR / Hope-RF radio modules.
  • License free use in Australia, Canada, USA, NZ.


These modems are designed to support long range applications, while being easy to use and affordable.  

These modems have been flying in various platforms and have demonstrated excellent performance in real applications. 

RFD900 modems are now available at: http://store.rfdesign.com.au

Support within APM planner and the radio configurator from Michael Oborne is already available.

It works seamlessly with APM planner, all radio Mavlink parameters are available.

Update, December 2014:  The RFD900+ with improved specifications is available now at:


Seppo Saario



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    • wow this is bad news. I guess the best solution is to just use 4g. 

      • Developer

        3G/4G is not a good solution for flying devices. Wrong placement on vehicle can cause interference with electronics. Another big issue is with bandwidth etc, none of the telecom carriers are giving any promises of data rates and signal is often lost on rather low altitudes.

        All telecom operators are expecting that all their mobile clients are on "ground" so antennas are naturally pointed downwards to maximize RF signaling. In cities where you have high-rise buildings you might get higher altitudes same goes on areas where you have some mountains closeby but on country side etc you can loose signal already on altitudes of 100-200m.

        For multicopters 100m is usually ok but fixedwings often tend to fly higher altitudes especially if doing mapping missions.

        So if you use mobile systems. Be careful and remember that you might loose all communications on low altitudes.

  • The cover on top of my RFD900 keeps coming off so I was thinking about taking it off and potting the inside of the unit with some silicone or epoxy that won't cause damage and then placing the top back on.  If I did this, would it cause the RFD900 to overheat?

    • Developer

      I would say: Don't do that!

      Most likely you either shortcircuit something on board or mess it's RF design and tuning. RFDs have specially designed RF PCBs and adding more material on it would most likely kill it's original design as epoxy/silicone will definitely alter resistances etc on board and components.

      Why don't you just add small solder dots on the metal EMI shield. That would not cause any bigger harm..

  • Hi !

    I have a new problem. I bought a rfd900+ telemetry for a plane. My ground station has a rfd900 (old version). The first times everything was working very well. But now there are serious problems. I did several test... I took from a friend the non-original 3dr telemetry (915 mhz) and I use it on my computer.

    My test results:

    Plane: Rfd900+       Computer: Rfd900 (old version) Weak rssi

    Plane: Rfd900+       Computer: 3dr Weak rssi

    Plane: Rfd900(old)  Computer:3dr Good rssi

    All antennas works well (I test it) I understand my Rfd900+ telemetry has a problem. I install to rfd900+ a new firmware (1.9sik rfd900a) and I check all settings but the signal qualty problem not fix.

    What do you think about this problem. Is it hardware problem or software problem ?

    • Enes,

      I don't know if it relates to your problem, but I found that my RFD900+ radios will not work with either my RFD900 or my 3DR radios unless I turn off ECC.  With ECC disabled, they all work together just fine.


      • Admin


        I was told the same thing by Event38 when I asked them why their version of the RFD900+ telemetry radios would not work with my 3DR telemetry radios.


        TCIII AVD

        • Enes,

          How weak is your RSSI?  I have noticed that at close range the signal is weaker but then as the distance increases it gets better.  I don't know what power output your using but that has been my experience.  I actually cannot connect to mission planner unless my vehicle is a good way away from me or if in my house its a few rooms away with the doors closed.  I have also read about the ECC problem with using a 3DR radio and a RFD.  Just what I've seen.


          David R. Boulanger

  • I have a problem with the telemetry logging of the RFD868+ on Pixhawk.

    If I look at the logs from a 3DR radio it looks like this:

    3702175986?profile=originalBut if I instead fly with the RFD868p it looks like this:


    Do anyone know what the problem might be?

    Edit: The communication was working fine on both flights

    • I have now verified that if I use the RSSI debugging functionality with AT commands the data looks good, RSSI is around 250 and noise around 60. So it is something in the pixhawk logging.

This reply was deleted.


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