Too much problems with base noise using RDF900 as ground rad


I re-post here a question about high levels of base noise with my RDF900 that I already posted in DIY Drones forums, without response until now ( … 5#comments). Hope here someone could help me with this problem.

I have just bought a RDF900 for use it as ground radio and my first tests are very dissapointing because of what I think that is an unacceptable local RSSI noise. Although the mean noise is around 40-60, what is little bit high but between the normal range, as I have readed you in some place (in this or another post, I don’t remember), it fluctuates a lot with frequent peaks over 80-100 and it causes a lot of errors and a very short range (much less than expected). I also have have high peaks of remnoise.

Please, find here-attached tlog of a flight and a picture or a graph of radios performance along it.

I have tried different configurations, firmware updating, conections in different PCs or laptops but I still have the same problem and I don’t know how to proceed to resolve it.
Next I told you what is my setup:

  • Base radio: RDF900 with original dipole antennas (from Firmware updated to SIK 1.9 through Mission Planner 1.2.99 and Default Config. Connected to PC through FTDI usble cable (with a ferrite)

  • Air radio: 915Mhz Radio Telemetry Kit, also updated to SIK 1.9. and a ferrite in cables to APM. It is installed in a quad with APM 2.6 and arducopter 3.1. I am ussing 5,8 Ghz FPV system and MinimOSD connected to APM trough an Y cable in the Telemetry port.

I usually set the ground radio over the roof of my car, at a distance of about 1,5 m from the laptop.

So, my questions are:

Could it be caused by interferences with GSM network (Spain)?
Could it be resolved by a different config or by another firmware?

Hi. I had somewhat disappointing results too at first. Line of sight is important. But another thing was for some reason the radio config tool in MP would not turn the RFD900 to max power. It went only up to 20. I thought this was max until I had it connected to a much older version of MP on another computer and noticed it went up to 30! The first thing I noticed was it actually got hot. Not too hot but noticeably warm. I have not had a chancy to fly yet but I can tell just from the fact with it in the basement and me outside way back behind my garage it was still around %90! I was using MP vs 1.2.53 you can find that here … ter?page=2

Another thing I noticed is the same radio [ i.e. same settings ] connected to my tablet does NOT get warn. So I’m pretty sure the tablet doesn’t supply it with enough current so I will need to get a better power supply. I will use this … 43c81289f7

Could be it’s none of these issues and just noise but thought I’d mention that.

Hi govsux,

Thanks for sharing your experiences. I will try to power it directly from an UBEC as suggested although I am not sure that noise probles were power issues.


Would you mind posting a screen shot of your Radio Setup? Noise on the remote end is usually caused by some in-band Tx on your platform. Believe it or not, the minimOSD causes some noise for me.
I have the RFD 900 and go >5miles without issue. I use ONLY the RFD900 for Ground and the 3DR for Airborne.

I will post a shot of my setup as soon as possible but I agree that minimosd could be a source of noise. I will check it, thanks.
On the other hand, I have done some tests at home narrowing the frequency band from 915-928 to 915-916 and I think that noise is a little bit lower (with less peaks) but I must to test it in flight before any conclusion. Hope I can do more tests next days and I will inform you then.

You may also want to add a RFExplorer to your tool kit. It’s a fantastic tool for what your problem is.