Hi All,

Has anyone experienced range problems with the 433Mhz 3DR radio?  I get a solid initial connection but I can only get about a metre of distance before the signal drops out. I also have a 915Mhz radio and that works fine.

Here are the current settings. The remote also has the exact same settings.

I am hoping it is just a setting I have not set correctly.


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@Andreas Baumgartner

Good find, those are indeed 2.4GHz antennas. Specifically, they're called coaxial dipoles, which are used because they're cheap to manufacture and easy to connect to*. In the classical approach, the shield is pulled back over the dipole until the right length-- usually 1/4 wavelength-- is exposed. However, when manufacturing it's faster to cut the shield and solder on a metal barrel.

Here is a photo I took of a FrSky antenna I disassembled. You can see the construction quite clearly, where there is a center conductor, a barrel, and a blob of solder connecting the barrel to the shield. This is exactly what we see in those pictures.

*Since the feed runs through the shield the entire antennas is in a straight line, instead of requiring a T connection like you see in old TV antennas.


I'm having the same problems with the RcTimer 433 modules.
Guess what, bad antennas.
Thanks to the info of Andrew Tridgell I nailed it down.
By replacing the antenna all was working fine.

So Andrew, thank you for the troubleshooting guide!

Have you contacted RcTimer about their bad antennae?



I have the same problem exactly with RCtimer radios.

Where did you guys buy the replacement antennae ? i don't want to make the same mistake twice !

Not yet but I already left a bad review on their site

I once bougt these for another project.

They do fine. However the frequency range of these antennas is from 429 to 436MHz.
The radio modules work in a range of 414 to 454 so they are not ideal as you risk to get out of band.
This is something I still need to check. I'm also looking to these ones.

For the moment I'm using an SMA connector with a 17,3cm whip.
Radio modules range is from 414MHz to 454MHz which gives a wavelength of 181,1mm to 165,1mm.
The center frequency is 434MHz which results in a wavelength of 173mm.

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