The FrSky X9D Plus has a stock 2dB antenna which is usually good enough for most pilots but not everyone. When you are trying to push the limits of the range of your radio, you would want the maximum power you can get. Since the power output of the radio is fixed at 100mW, the best you can do is to upgrade the antenna to a 5dB antenna with a pigtail so you can even upgrade to a higher direction antenna if you ever require so.

In this How to series, we will look at how to change FrSky Taranis X9D Plus Antenna Upgrade.

Risk Warning

Please note that this is an extremely risky mod where a lot of people have reported damages to their Taranis radios after doing this mod. This is due to the extreme ESD sensitivity of the RF components in the transmitter part of the radio. These parts can easily be damaged with a small spike in voltage - like the electrostatic discharge from your body.

This is why I recommend using an “Anti-Static Wrist Strap” while dealing with sensitive RF components or any electronics as such. If your Taranis radio provides you with good enough range, then it is better to stay away from this mod since it is not a necessary mod for your radio.

 

PROCEED WITH CAUTION!

Why use a 5dB antenna in the first place?

The radiation pattern of a 2dB antenna is small and doesn’t provide the maximum range the radio can actually provide. This is due to the lower gain, which in turn spread the signal in more area rather than concentrating in a highly focused beam.

When you are using a 5dB dipole antenna in the place of the 2dB one, you are focusing the radiation pattern in a more concentrated beam which will provide more range in one plane while reducing the range on the other plane.

This is a double-edged sword, in one perspective, it will provide you with a longer range if you correctly align the antenna direction to your flying direction but on the other hand if the antenna direction is not in line with the direction you are flying, you will have worse reception than a 2dB antenna which spreads the signal a bit more.

The above images (courtesy of Oscar Liang) shows the radiation pattern differences in the 2dB antenna and the 5dB antenna. As you can see, the 2dB antenna has a wider pattern but has a shorter distance, while the 5dB antenna has a shorter pattern but in a long distance.

I would recommend getting a few types of antennas to find which one works best for you.

 

Disassembling your radio

To disassemble your X9D radio, first, remove all the screws on the back of your radio.

Once that is done, open up the radio carefully without damaging the wires. Disconnect all the connection wires between the two halves of the radio.

 

Desoldering the stock antenna

!!!Ground yourself before continuing!!!

The antenna wire is the thick black piece of wire soldered as shown in the above picture.
Carefully desolder the wire without damaging or disturbing the nearby components.

Once the antenna is desoldered, you can pull it out of the top socket. There are two clips holding the antenna in place, you just need to squeeze them with a pair of pliers and push it out of the socket.

The above picture (from Oscar Liang) shows how to remove the antenna by squeezing the clips inward to release the clip mechanism.

 

Adding the new 5dB antenna

Now you can repeat the steps backwards. First, feed through the pigtail connector through the antenna hole on the transmitter shell and then solder back the pigtail carefully to the RF PCB.

While soldering, the core wire in the coax cable should be soldered to the middle pad on the PCB while the ground shielding wire surrounding the core cable should be soldered on to the ground pads beside the signal pad on the PCB. This process should be done with extreme caution to not damage the components and remember to keep yourself grounded to avoid damage to the sensitive RF components of the device.

Once that is done, hot glue all parts well so as to protect it from being damaged.

 

Check SWR (RAS)

To check whether the installation process has been done properly, we need to check the SWR which is called the Standing Wave Ratio, it is the measurement that indicates the amount of signal that has been transmitted out of the antenna versus the signal being reflected back. Ideally, this value should be between 0 to 1.

If the antenna has been damage or the soldering has not been done properly, the SWR value will be greater than 1. Usually any value around 1 is considered fine just make sure it is not too great (like above 2 or 3). If you keep any metallic object near the antenna, the SWR will increase again, so that is fine.

You can check the SWR on your radio in the analog test page in the radio setup (page 7). It has been named as RAS in OpenTX or the Relatve Antenna Status.

 

In this article, we have seen how to: frsky taranis x9d plus antenna upgrade and why it would be useful for you and why the 5dB antenna would give better range than the 2dB and how you could do it carefully.