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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    • You should get much better range from the RFD900's compared to the 3DR style radios. Yes you can mix 3DR radios with RFD900's as long as you dont try the multi node stuff with the 2.x firmware.  I get around 1.5 times the range just with a straight and 90 degree quarter wave antennas but it depends on the environment you are in.  Once you lose radio LOS it will go downhill very fast.  Depending on your locality you maybe legally able to bump up the TX power, in Aus we can do 1W EIRP for 915-930MHz.

      From memory 20 will give you 100mW, 24 gives you just under 400mW and 30 gives you 1W.  Note that I use 24 (400mW output) with antennas with some gain to give me 1W EIRP.  On the land side I'm about to use a high gain antenna on a tracker and will drop it right down to less than 100mW output but the EIRP will be close to 1W.

      So no simple answer I'm afraid it depends on the environment you are in.

      • Thanks for your response Chris.

        what configuration should I use in mission planner for good range in a rural area?


  • It has been a long time since updates!

    We have been working on a lot in the background.

    A 900 MHz RCLink solution will be available very soon, within the next 1-2 months.

    Telemetry plus concurrent PPM passthrough.
    Modems with higher data rates and encryption (finally) are in the works.

    We have prototyped the units and pretty happy with their performance.

    Sorry for not revealing too many details just yet, but, letting everyone that we are very much on the case.

    If there are some people keen to beta trial units and give them a good workout, please send a PM..

    Also wishing to thank you for your support over the years.


    • Hello, I benn using a pair of these 900+ units with great results, even when I only use one in my Iris+ for Mapping I get a lot more than the normal 3DR Radios can give me, I will love to Beta test any sample, Cristian

    • Seppo, a couple other questions - I assume encryption will only be available on the "+" version, true?  And is there any impact on the throughput?



      • Dan,

        The new modem will be a RFD900x not a RFD900+. The RFD900+ is the existing modem and I'm not completely sure of the state of encryption on that version, but I can tell you about on the RFD900x.

        On the RFD900x encryption is 128 bit and will have a slight impact on throughput. It depends on the data rate, i.e. lower rates (4,64K) it will be less noticeable and for higher rates (128-500K) it's in the order of around 10 % of the throughput. Note that the RFD900x is already substantially better than the RFD900+ for utilization of the available air rate so with encryption on it will likely still be better then the RFD900+. More data will be released, hopefully with some actual numbers once the product is released.


        • Thanks for the info, Kent!

    • Hi Seppo,

      Yes, a long time - but good to hear the news!  Over the years, I've purchased 3 RFD900s from you and wanted to know if the Telem + PPM passthrough is a firmware update.  My modems are all RFD900, not RFD900+, if that makes any difference.



      • Dan,

        No PPM is not available on the RFD900+, it is only for the new RFD900x due to be released soon... 

        I don't think this will be possible on the 900+ due to size constraints and other issues.



        • Hmmm ... I wonder if Seppo would take a 900 as a trade-in on a 900x ;-)  Kidding! 

This reply was deleted.


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