In an effort to create affordable solutions for emergency service pilots operating drones for fire and search and rescue groups, here is my latest budget loving Frankenstein solution. The dedicated equipment for this comes in at a grand total of $76, not including parts used for other things.
The Wake Forest Fire Department coverage area has some large lakes in it. We also have to prepare for missing person operations as well.
But the communication solution I hacked together here may have some broader applications as well. For example, it can be used to communicate with people on the ground who are not victims, but searchers. It could even be used by law enforcement.
My goal in creating a communication solution was to allow us to give direction to a remote victim. The first need for this was in this water rescue flight.
I was able to reach the victim in that rescue in 19 seconds but unable to communicate with her. We had to wait 10-15 minutes until the fireboat arrived to do that. The call was an opportunity for a solution and here it is.
Rudimentary communications are possible using this setup. It does not allow two-way communications but we can ask the victim questions and let them respond by raising their arm. More importantly, we can give the victim advice on what is going on, our plan of action, or what do do when the life vest or supplies we need to fly to them arrive.
The configuration shown here allows the rescue team to clearly be able to be heard on the ground from 200 feet AGL and higher. This allows you to fly avoiding obstacles but yet able to communicate clearly with people on the ground.
You can see the final solution in operation in this video.
One of the advantages of the Matrice 210 we fly is the payload capacity. The set up below comes in at 3.29 pounds which is not only very manageable with the 210 but the test video above was shot on a very gusty day. The UAS handled it perfectly fine.
You can see how gusty the winds were when we tested the final set up.
The communication setup consists of a Pyle PMP59iR megaphone for $49. The magaphone is rechargeable so no need to carry heavy batteries.
A 2.5 mm to 3.5 mm adapter cable at $6.
A set of BoaFeng BF-8885 walkie talkie radios at $21.
One or more nylon straps at $14 for four.
How to Assemble the Rig
1. On the megaphone set the play button to on.
2. Turn megaphone power on.
3. Connect adapter cable to 2.5 mm output on the walkie.
4. Plug 3.5 mm end of the cable into the megaphone and bundle adapter wire and walkie together and secure on the megaphone.
5. I use a small bungee cord with a key ring tied into the center of it. String the bungee across the skids and secure.
6. Clip one end of the nylon strap to the key ring.
7. Clip the other end of the strap to the strap on the megaphone. We tied a knot in the megaphone strap to connect the strap hook to so it hung at a slight angle instead of straight down.
8. Turn on both walkies and confirm they are on the same channel. If you test the walkie near the megaphone on the ground you will get sharp feedback. Works best when separated by at least 150 feet.
9. Upon initial set up for your drone, be sure to make a log entry in your aircraft log book that you confirm the equipment is safe to fly after you test it.
BONUS TIP: Make sure you lay out the strap so it has some tension on it before you take off and in the video watch how I land and make sure there is tension on the cable. Otherwise, it could be possible to suck the strap into your propellers.
Feel free to email me with questions using the form below.