Fixing 2.4Ghz Antenna on Radio Receiver

If you ever damaged or cut the antenna on the 2.4Ghz Radio receiver in a crash, or chopped by spinning propellers, don’t worry. You might be able to fix it without buying a whole new receiver or antenna.

  • An RX antenna is a pretty common coax cable, it has a layer of protective skin on the outside provides physical protection (plastic)
  • And the next beneath the plastic there is a layer of metal wires which is used to shield the the wire. It prevents outside noise from getting in or out because it’s grounded
  • Remove the shielding, you will find a thin wire, that’s your antenna! The length of this exposed wire without shielding determines the wavelength it’s tuned to

Making or repairing 2.4Ghz antenna has the same principle as 5.8Ghz antenna mentioned earlier. All you need to know is that the antenna needs to be 1/4 of the signal wavelength, which is 31.23mm for 2.4GHz. (put this in google “c / 2.4ghz / 4” if you don’t trust me :D )

Take a clean cut at the end of the broken antenna. Measure 31.23mm from the end, and carefully cut and remove the surface plastic layer, and the shielding. only leaving the centre wire exposed. It doesn’t matter how long the whole antenna wire is, as long as there is only 31.23mm wire at the end that has no shielding. A tiny bit longer or shorter, your antenna will still work, but you will lose some range, just remember to closer the better.

Beyond Repairable? Buy Replacement

Alternatively you can just buy these 2.4Ghz RX coax antenna as replacement, such as Frsky receivers. Purchase from

25 thoughts on “Fixing 2.4Ghz Antenna on Radio Receiver

  1. Ben

    Hi Oscar,

    I am currently in the process of waterproofing my multirotor.. it is hard to do that with my Stock Futaba Rxs coaxial antennae. My thought is to use a SMA to U.FL wall panel adapter mount and using a more traditional plastic 2.4 antenna instead. Is there any reason I can’t do this or anything i need to take into consideration?

    Thanks for your time.

    Reply
  2. Hamidreza

    Hi dear,
    Last week i had rc airplane crash.
    Till know i cut around 6cm of the reciever antenna because of crash.
    The people there said that i crashed because the lenth of the main wire anttena is not long enough. But i should mention that always i had 3 cm unshield anttena our of the rc airplan rather than the shieldet part.
    The question is that the lenght of the antenna wire is important or just it is important that there be 3cm unshield of antenna wire?.
    Thanks.

    Reply
    1. Oscar Post author

      yes only the length of the unshield part of the antenna matters, but I guess if the antenna is longer, the less probable signal gets blocked by aircraft material.

      Reply
  3. KWAD

    Hi Oscar,

    If I’m correct, the shielding on an antenna needs to be connectet to a ground? If so:
    I just received an Devo-RX601 receiver for my devo 7 controller to use in a Quad, and noticed that the antennas are really short. I need them to be longer. I have several antennas that is made for Rc 2.4GHz receivers, so I know that they are correct for the purpose. However, the antennas that followed the receiver are so short, they are not shielded (or coaxed?). Therefore the receiver has no ground solder point for the shielding. Would it work if I connected it to another ground that is somewhat connected to my battery? Let’s say the ground connecting to the receiver?

    Thanks on beforehand!

    Reply
    1. Oscar Post author

      Hi, yes the shielding needs to be connected to ground.
      Yes ground should be common on the receiver PCB, so any ground should do.

      Reply
  4. Mark Ramsdale

    Hi Oscar
    I have a walkera runner 250 and a 250 advanced with gps. Not had much luck with the gps version so far but the earlier model has been flying fine even after a few crashes and rebuilds. But I noticed on my earlier model both ariel wires wasn’t stripped down at all. They had the full outer plastic casing all the way to the top but I was still flying using both my devo 7 and devo 12E well over half a mile with no issues. The other day I completely cut one of the wires off after a crash all the way down to the receiver unit so there was only 1 wire left. It still flew out over 1/4 of a mile before ran out of batteries. Anyway I have bought some replacement 2.7 wire to repair it and am I correct that I can completely remove the wire from the circuit board and just re solder my new wire to the larger of the 2 connections on the circuit board as this wire doesn’t have the outer shielding so will only have 1 connection to the board instead of 2.

    Reply
  5. Fivedragon

    So I just get crashed and my exposed antenna wire is gone. So if I make that 31.23 mm shield cut on that broken antenna, its gonna make the total length of wire shorter on one side. Is that okay? Thank you.

    Reply
  6. Stan

    Hi Oscar! I am new to the site and have an antenna question. Some back ground I am building a sailing craft and wish to keep the xr8 2.4 receiver inside the vessel’s hull for waterproofing. I want to put a 2 meter extension on the antenna so it is well out of the water. Can you explain how this could be done. Also what are the implications of occasional spray contacting the exposed antenna?

    Reply
  7. Rafal

    Hi Oscar … thank you for your blog.

    Can I use an old 2.4 TX whip antenna (like from a Taranis Radio) without the surrounding plastic casing off course :) as an RX antenna?

    I have one of those and I’m asking because from the tip of the weird bullet dome to the tip of the actual antenna core it’s measuring 2.55cm not 3.123cm like you said.

    Reply
  8. Revomikey

    Tell you what though Oscar, i have a thought….. (Dangerous :) )

    When the cable gets too short to facilitate 32mm whats to stop me unsoldering the coax completely and just adding a normal piece of single core antenna cable to the center core joint of the pcb and just trimming that back to 32mm, eliminating the outer core completely.

    Would this work?

    Reply
  9. RevoMikey

    Hi Oscar, great page, thanks.

    I never knew the active part of the antenna was just the “open” side, I now have my walkera runner 250 back in the skys.

    Top man, many thanks.

    Reply
  10. Jake

    Thanks for all your posts and pages! Very helpful overall… So I cut my antenna the other day in a crash. If I understand correctly you can remove the plastic wrap as long as you leave the same amount exposed? My question is can I solder on a wire and then expose the very end of it to match the preferred length? I had a longer antenna and would like to replace it to the same length if possible. Thanks!

    Reply
    1. Oscar Post author

      i think so Jake that should work, after you done that just do a range test and make sure that’s working reliably i guess

      Reply
    2. Travis

      It has to be a shielded coax antenna wire with the shield contacting the receiver’s ground. Standard wire does not have a shield to ground.

      Reply
  11. Pakal

    So, basically the “working” part of the antenna is only the exposed wire ? Does it mean that I can hide the first part of the antenna under the frame and really just care to properly place those 31 mm of exposed wire ?

    Reply
  12. Charles

    Hi,

    You have so many cool info. I’m a newbie
    in the RC community. My question is,
    can I tin the expose wire? What will happen if its tinned?

    Thank you

    Reply
  13. Jiri

    Hi Oscar

    You have one small mistake at last sentence. Longer antenna means lower resonant frequency ;)
    In reality that´s not so critical, antenna will be OK within 1 to 2 mm tolerance.

    Reply

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