On pictures of 3DR’s IRIS you always see the telemetry antenna in the back of IRIS pointing straight up (See Figure 1).
Turns out that this configuration is actually a bad idea. Especially with the long legs (as depicted in Figure 1) attached, IRIS is very prone to flipping over. In that case it will land on the Telemetry antenna and over time damage it. The result will be that the antenna connector detaches from the actual telemetry transmitter due to the force of impact (See Figure 2).
At this point you will need to spend 50 USD + shipping to get a replacement transmitter. As you can see in Figure 2, I have broken off the antenna mount myself and had to replace the telemetry transmitter. In this post I want to show you how to prevent your telemetry antenna from being damaged.
Required materials and tools
No additional materials or tools are required.
Place the telemetry antenna towards the right side, until it touches the top shelf (See Figure 3). Ensure that the antenna is firmly attached to the telemetry module and doesn’t wobble around. Also make sure that the antenna is placed under the back-right propeller and stays clear of it (See Figure4).
It would be ideally to place the telemetry antenna downwards, but this is not possible as the telemetry module is mounted to far towards the front. Also with the current placement you are not able to tighten the antenna without removing the top shelf. This is an issue as the antenna apparently rattles loose during shipping.
But placing the antenna in the above shown position will ensure that during a flip – e.g. during landing or take-off – IRIS cannot fall onto the antenna and damage the connection. Signal reception will not be noticeably impacted by this change.
Interestingly I have seen 3DR staff fly IRIS in the Gimbal + tall legs combination also with the antenna pointing towards the side as depicted above.