If you ever damaged or cut the antenna on the 2.4Ghz Radio receiver, due to crashed, or sucked by propellers, don’t worry, you might be able to fix it without buying a whole new receiver.
Building or repairing 2.4Ghz antenna is the same as the 5.8Ghz antenna mentioned earlier. All you need to know is, the antenna needs to be 1/4 of the signal wavelength, which is 31.23mm. (put this in google “c / 2.4ghz / 4”)
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 shileding. only leaving the centre wire exposed. It doesn’t matter how long the antenna wire is, as long as there is only 31.23mm wire at the end that has no shielding. On the Frsky Receiver I use, the length is a bit longer, maybe they use slightly lower frequency than 2.4Ghz?