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Hello, if I wanted to maintain constant radio contact with a device 15km (~9 miles) away, and I had no guarantee of line of sight, what would be the best way of achieving it?

Is it best just to get a very large antennae or would I be better off having an intermediary device to bounce the signal off (attempting to the intermediary in a position with LOS)?

Also does anyone have any textbooks on this sort of things they would be willing to share?


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I would love to say "Get your HAM licence and gear up with some nice SDR, amplifier and antennas " but the reality is that a GSM module from china can be had for less than 5$

The A6 from AI-Thinkers and soon to be available A7 (added GPS) will have all you need to stream information to your server at fairly low power using the phone network. These days data only sim are pretty cheap and "pay as you go"

If this is not what you want or need (GSM is not available everywhere) then look for P2P directional antennas in order to minimize the power needed between you and the thing you are tracking.

Look on eBay for old military radios, sometimes good bang for the buck.

Post updates/more info as you go, I am interested to see what you do with this!

PS: if you are at all interested in SDRs, get an RTL-SDR, super cheap and well documented/supported!


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Thanks heaps, I'll definitely look into the A7. I don't think the GSM will be available, so P2P will be worth investigating.

I'll keep you posted, and let you know what works for me. Cheers!



this is from Oceania coastal channels that I was scanning, do you want to see the others?


Neat! What kind of gear do you have?

Could you post pictures directly instead of Amazon Drive?

More pictures would be great!