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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I am using RFD900 from jdrones.com and minimosd v1.1 on my apm2.6. I am requesting a wiring quary. The splitter cable minimosd came with has this cable. There are four cables for telemetry whereas my modem has already 5 wires. How do I connect them?


I think the only required connections are RX TX 5v and  ground. Here's a pin out hope this helps


Is it the same with rfd900...in your attachment it's 3dr telemetry module.

This makes me wonder what the power output limit of my tablet and OTG cable is. I don't see myself needing the full 30dBm output but I wonder what the amp draw limit would be to much for a mobile device. Figure 4.2 from the data sheet shows 0.2A as the lowest current draw which may be possible. Trees and a big hill here keep my stock 3dr units from reaching.

Hi Seppo,

I’ve just received the RFD900 warranty replacement and free antennas

Thank you very much

I have a 8kg octocopter and I try to get the best range possible with your RFD 900 Modem

On the octocopter, the two antennas are separated 40cm and I can place on on vertical polarization and the other on horizontal polarization

I have no problem of weight on the octopter, I can even place a 100 grams antenna, or a 40cm antenna

Now I have 3x 2dBi antennas, 2x 3dBi antennas and the RFDFELX antennas you’ve sent to me

My question is what kind of antenna should I use on the octocopter and on the base station to get the max range possible ?

Do you think that this kind of antenna could improve the range: http://www.readymaderc.com/store/index.php?main_page=product_info&a... ?

My last question: when I use the 30dB setting for rf power, I see that the RSSI is decreasing, I got half the RSSI  than with 28 or 29dB power, do you think that the 500mA USB powering is the cause ?


Do you think that the Pixhawk supply enought amps for RFD900 at 30dB on the telemetry port ?

Do I have to use a UBEC instead of the telemetry port supply ?

Hello Zach. I sent you a request but didn't include why. I ran across this post and wanted to know if you would be so kind to try and assist me with my JDrones RFD900 radios. Can't connect via COM7 57600 and this is what has happened so far:

1) Ordered radios with Pixhawk FTDI cable

2) Replaced cable on air radio with Pixhawk cable and connected (get solid green light when craft is powered on)

3) Connect GS side radio and get blinking green light

4) Loads settings from GS radio but just a few fields of data (may just be default) of air radio side

5) Upgraded firmware on GS radio using 3DR radio tool

6) Installed latest drivers from FTDI site (2.08.28) is no longer listed

7) Plugged FTDI USB cable into air radio to check settings (based on post I read) but radio can't be found/accessed. Also shows solid green led when plugged into GS via USB cable.

NOTE: It seems odd that the air radio always has solid green while GS modem blinks. I would think especially connected to GS they would have the same behavior.  Any ideas of where to go next by you or anyone else would be greatly appreciated.



Jon I'm sure this ins't the case but what the heck... I had similar issues once only come to find out I forgot I had another radio plugged in on another computer so the connections was not working right with 3 radio's at once. Just a thought :]

I thought about that too. I have a plane with a couple radios but they are disconnected and not powered on. It seems very odd that I plug in GS radio and get flashing green and can access, unplug and plug in the 2nd and get solid green and no access. Very strange. I checked FTDI cable multiple times and just can't get it to connect.

Thanks for your response!


Anyone having troubles connecting to their computer?  After two years I'm getting "usb device not recognized".  Manually DL's the FDTI driver which will allow me to connect, but the next time I plug it in I'll get the same message.  The only difference is now I'm using Windows 8.1pro instead of Windows 7.  Happens on both my laptops.  Last mapping job I did I has to switch to a 3DR modem, drastically cutting my range down.

Pixhawk won't supply power to your modem.  Pull the jumper and power with a bec.

I power my RFD900 from the pixhawk - haven't seen any issues. can you elaborate?

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