I’m trying to figure out the regulations around tethered drones. Specifically, I’m interested in deploying one from a generator to hold a lightweight antenna at a high enough altitude for emergency communication during disaster response.
Does anyone here know what the rules might be in ham radio circles? And how long could a drone stay up if it’s powered by a tether?
I’d probably go with a balloon for this kind of setup. Fill it with hydrogen (yeah, I know… risky). There are existing regulations for tethered balloons that could apply. Also, putting a beacon on it and filing a NOTAM wouldn’t be a bad idea.
@Wren
This is exactly why I didn’t just Google and move on. I hadn’t even considered this option—really cool idea!
Mason said:
@Wren
This is exactly why I didn’t just Google and move on. I hadn’t even considered this option—really cool idea!
Definitely seems like a cheaper and more reliable way to do it.
This almost sounds like a high-altitude pseudo-satellite. Not sure how well it would work that close to the ground, though.
albright said:
This almost sounds like a high-altitude pseudo-satellite. Not sure how well it would work that close to the ground, though.
Nah, if it’s just for boosting communications, you wouldn’t need to go that high. The gear might be too heavy for a drone to handle, though.
@Jensen
What kind of antenna are you thinking of? Might help to get a better idea.
albright said:
@Jensen
What kind of antenna are you thinking of? Might help to get a better idea.
Just look up basic 2-meter antennas. The weight and wind resistance would make keeping it stable a nightmare.
A cell booster, on the other hand, has potential.
@Jensen
Curious—how stable would it actually need to be?
Fox said:
@Jensen
Curious—how stable would it actually need to be?
Not totally sure, but a 2-meter aluminum antenna weighs around 0.75 kg and would catch wind like a kite.
I’d be worried about it dragging the drone around in anything more than a light breeze.
As a person who designs and builds commercial drones (in the 13.5kg range) I’d feel pretty confident in putting an antenna like this one in the air. While our drones don’t carry antennas for 2-Meter HAM, they do fly in winds upwards of 35 m/s without issue.
I don’t think this would be all that hard of a problem to solve.
If you could counteract the torque from wind resistance and find a strong enough mounting point on the drone, I guess it’s possible.
Realistically, though, just hanging a cell booster from a cable or small cage would be way easier and cheaper. I could 3D print something like that and throw it on my Matrice 350 in a day.
Props to you, though—custom drone work sounds like an interesting field!
I think they already do something similar for cell communications.
Bailey said:
I think they already do something similar for cell communications.
Yeah, I’ve read some articles about it.
I’m really curious how long a drone optimized for tethered flight could stay up. Environmental factors like motor heat, wind, and rain would be big issues. A few hours is definitely doable… more than a day? Not sure.
A cold 40°F day vs. a hot 90°F day could make a huge difference in flight time.
Edit: Looks like this company specializes in it—24-hour flight time! https://elistair.com
@Onyx
I think it’s definitely possible. Since power isn’t an issue, you could oversize the motors, use larger propellers, and even integrate active cooling.
The weight of the feed line as altitude increases will probably be a bigger issue than the antenna weight itself.
How long it can stay up really depends on how high you need it. The higher you go, the heavier the power cable gets, which means the drone needs more power to stay up, which in turn means you need a thicker (and heavier) cable to carry that power.
Let’s say you’re aiming for 200 feet. Based on a Yuneec H920 as an example (since it’s decent for lifting), you’d probably need 14-gauge stranded wire to minimize voltage drop. That alone would weigh around 7 lbs at 200 feet. If your antenna needs another strand of wire, now you’re at 10 lbs.
If the cable can handle the current, you could theoretically stay up indefinitely. But if you need thicker wire (like 12 or 10-gauge), now you’re looking at a drone that can lift 20–25 lbs.
It’s possible—these setups exist for temporary communication deployments—but it’s a tough challenge for a private individual. And as far as regulations go, it would still follow standard UAV operation rules.
FLIR is releasing a tethered option for the SIRAS UAS. It’ll go up to 230 feet. It’s pricey, but they were offering a special deal for agencies on the SIRAS package—no clue if they’ll do the same for the tether kit.
Yes, tethered drones have different regulations regarding altitude and monitoring. They’re already being used for mesh networks and repeaters.
