I crashed my SG Adventure FPV quad last week and broke the two antennas of my FrSky D4R-II receiver. As I don’t wanted to wait for a new receiver, I decided to repair the one (the connector of the second one was totally destroyed so it couldn’t be repaired).
The size of the broken 2.4Ghz was about half the size of the original one after the crash. There are two possibilities in general: buy new one and replace it by removing the old one from the receiver connector or cut the broken antenna, so its length is appropriate to the wave length.
The wavelength by 2.4Ghz is 0,125 meters (125mm). The antenna should be 1/4 of the wavelength. In the FrSky receivers it is a bit more. So I just needed to cut the rest of my antenna to 31,25mm. By cutting I mean firstly to remove 31,25mm of the plastic/PVC. The next layer is the shielding. Remove this one too to the length of 31,25mm. By doing this the last 31,25mm should be the dielectric and the wire in it, that is the “active” antenna. That’s it. Now the antenna is functional again.
Note that there is a discussion if only the last unshielded 31,25mm are important or the length of the shielded part too. Didn’t find an answer on that question (even in the rc-groups thread about that).
0 Comments.