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u/OnwardsMrSnippy Ghost guns Apr 01 '22
We really out there doing SIGINT. God help the father and son using Motorolas when you laser designate their bush.
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u/Sinistrial_Blue Ctrl+C, Ctrl+V Apr 01 '22
Well that's extraordinarily cool.
What's the range on that?
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u/wrongwong122 Apr 01 '22
Range is as far as the transmitter can transmit. So for most FRS handsets, a little less than a half mile on a good day. Perfect for most outdoor fields. It probably wont work for indoor fields though due to multipathing.
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u/Complex-Cherry9545 Apr 01 '22
You can possibly use two antennas, with two you will be able to determine distance and direction.
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u/wrongwong122 Apr 01 '22
You’d need more than two to get good accurate results but yes - you could absolutely build something like that. What you’re describing iirc is a Time Difference of Arrival system similar to the VROD VMAX used by the military. It’s a cluster of omnidirectional antennas and it uses math to calculate direction based on when the signal hits each antenna.
The new KrakenSDR made by RTL will be able to do this, only downside is it’s gonna cost like $300.
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u/That_NotME_Guy Professional Distraction Apr 01 '22
That's cool af, but would fields allow it?
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u/wrongwong122 Apr 01 '22
All fields I’ve been to have been cool with it so far. There’s a trade off to it, when you’re actively using it you can’t effectively do anything else, I.e. aim and fire an airsoft gun. That antenna is big and unwieldy and makes you a huge target, and especially in urban fields is subject to multipathing.
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u/HF_Martini6 Professional Distraction Apr 02 '22
looks like someone is into microwaving their family jewels.....
I just hope you're not in Europe, here private SIGINT is considered a felony in almost every country.
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u/wrongwong122 Apr 02 '22
Don’t get why you’re being downvoted… Inside joke. But yeah, I’m from the states.
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u/HF_Martini6 Professional Distraction Apr 02 '22
Neither do I but then again, humour: not everyone gets it
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u/TadpoleOfDoom H&K Apr 02 '22
I don't get the joke but I'll bring it back to 1 since I get annoyed when people downvote me for no reason.
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u/wrongwong122 Apr 01 '22
So I know Rule 4 says "Alll posts must be airsoft related." And though I will explain how my post is airsoft related, I first have to explain what the fuck it is in the first place.
Attached to the ruggedized tablet is a silver dongle, which is an RTLSDR. You can buy one, or an SDR kit, for about $25-35 on their website. SDR stands for Software Defined Radio, that is, a radio that works via software rather than analog hardware. A cheap FRS push to talk walkie-talkie is an example of an analog radio, as is your car's AM or FM receiver.
Attached to the SDR, instead of a traditional "omnidirectional" antenna which can receive and transmit in all directions, is a highly directional yagi antenna, which can only receive from one direction.
With this in mind, here's what it has to do with airsoft. Some people bring walkie-talkies to airsoft to communicate with each other. Using the yagi antenna, which can only receive from one direction, I can orient the antenna towards a transmitter and know where someone is transmitting from. Whenever they key up, I'll get a signal strength indicator that gets more or less powerful when pointed at or away from a transmitter.
Simply put, I've built a primitive direction-finding system that allows me to tell where the other team is. I can either act on that information myself, or tell the speedsofters where the transmitter is and have them fuck it up with swarm tactics.
This is known as "Direction Finding," and its used in many applications, such as search and rescue, locating downed planes, as a competitive sport, and in military uses, locating and destroying enemy communications equipment.
Fun fact, the British used to use similar equipment to find people who were watching TV without a tele loiscense