In this tutorial you will learn how to make a successful frsky xsr replacement antenna, in the case you have rip out or cut off your XSR receiver antenna.

First, let's see what type of antenna and which length of antenna you need to replace your broken antenna.

 

How to choose the correct antenna

The XSR receiver uses a type of antenna called monopole, which consists of an inner core which transmits the information and a is covered by a wire mesh which is grounded.

It is highly recommended to use genuine frsky antennas.

Ideally in order to get the strongest signal received by our antenna, we must have an antenna from a length where the inductance and capacitance in the antenna are equal, as the additional capacitive or inductive will result in a performance degrade.

To choose the correct length of our antenna in order to make a successful frsky xsr replacement antenna we have to consider the wavelength of the radio wave, which resonant frequency is a multiple of the signal wavelength, where the inductance and capacitance in the antenna are equal, in our case we will take quarter of the lenght.

It is also important to bear in mind that when we talk about calculating the length of the antenna in order to make a successful frsky xsr replacement, what we are calculating is the length of the active element, in other words, we are looking for the length of the conducting inner core which is not covered by the braided shielding.

So as the XSR is tuned to work at the frequency of 2.4GHz, the quarter of the wavelength is 31.2mm long which is calculated from: (the speed of light / (2.4 gigahertz)) / 4 = 3.1228381 centimeters).

As we can see, theoretically the ideal length of the active element is 31.2mm, but, as the XSR receiver is not tunned equally because it has some inductance in purpose, the optimal length for the active element in order to make a successful frsky xsr replacement  antenna without degradation on the performance would be 26mm, which is the stock antenna length.

Apart from that, other thing to take in consideration is the type of connector of the antenna, which can be an IPEX connector that you will have to cut later on, or you can also buy a Direct-Solder antenna which is the most convenient election.

To sum up, to make a successful rx  antenna you need a monopole antenna, with an active element of 26mm, and a remarkable thing to take in consideration is that the shielded wire can be of any length as it does not irradiate.

How to replace the antenna

The first thing in order to make a successful frsky xsr replacement antenna, is to start by unsolder the old antenna you want to replace.

Now, if you have bought an antenna for frsky xsr with an IPEX connector, you will have to carefully cut it and prepare it to solder it, but if you have bought a Direct-Solder antenna you can skip this steps.

You can start by peeling off first the plastic jacket by about half centimeter, to make this step easier without chopping the shield, it is recommended to use a lighter to burn the plastic in order to remove it easier or a precision knife to cut it off.

Then, pull the exposed shield in one way, and twist it a little bit, and tin it. Afterwards, remove just one millimeter of the clear jacket in order to avoid the shield to touch the core and you are done, you have prepared the antenna for direct soldering in order to make a successful replacement antenna.