As we see digital radios beeing used by emergency services whithin the next couple of years here in germany, we wanted to have some experimental plattform to carry a DMO Repeater. We thought, this is a good way to learn something about the TETRA System, it's range and it's characteristics when used in the mountains.
So the sonar now is integrated to have better autolanding capabilities, some antenna is mounted on the back above a copper plate and some bracket was 3d printed to bring a handheld radio with Repeater/Gateway options up in the air.
Maybe we will put some skiers on it,
have fun in the mountains and take care,
Tom
Comments
Thanks David,
Reading links in ur comment.
Meanwhile I needed a no brainer project and had DJ-G5 sitting idle , so thought about this. I just have to find balloon big enough to lift 5k.g max to try this.
@Thomas:
Outstanding! Really like the idea of an autonomous quad performing station keeping to serve as a rapidly-deployable antenna mast.
@Morli:
Balloon-borne crossband repeaters are amazing to work with - I've had the opportunity to work with a couple of them, and the ability to go for hundreds of km with just a handheld is truly fantastic. In case you haven't found it, here's a reference design available to the public: http://www.eoss.org/hardware/crossband.htm Another design that isn't published (unfortunately) used a pair of Alinco credit-card transceivers with a simple key circuit on the downlink that was tied to the Rx activity LED on the uplink and an audio patch cable. 300mW was all it took for full-quieting communication from 100,000 ft.
I tied my cellphone, whilst acting as a WiFi hotspot to a kite one year when we were snowed in here in order to get a connection. A fairly persistent solution limited by the cellphone battery and distance the WiFi bit would work for.
Keep us in loop. Good luck.
I don't how legal it would be to put tetra repeater up in air but I thought of putting a crossbander( Alinco DJ-G5) up in a balloon/blimp gondola( flight endurance being issue with other platforms) for HAMS during emergency /disaster support exercise. It is idea I need to try some day soon after due consideration from authorities.
Cheers