In a well-known Youtube channel there is a scene where a scooter had some kind of short circuit caused by magnetron used as a weapon from a distance. I never saw this channel to have fakes but one guy does not believe, saying:

OK, rough calculations erring on the side of the fake one. The real one shows a magnetron from a microwave oven, so let's say that's a really shitty one with 650W output. Let's assume you need the same amount of power to fry a bike's electronics as you do to light up a fluorescent tube. You would actually need a hell of a lot more, but we are being (very) generous and lazy when it comes to research.

In terms of distances, I'd say the tube video is about 1 metre and the bike one about 100 m. But let's be generous and lazy and call it 64 metres. For each doubling of distance, you need to increase the power by 4 to get the same field strength. So 2 metres would need 2,600 watts, 4 metres needs 10.4 Kw, 8 metres needs 41.6 Kw, 16 metres needs 166.4 Kw, 32 metres is 665.6 Kw and finally, the distance from the device to the bike, 64 metres would require a power supply that can generate 2.662 Megawatts of power. So, for a 9V battery that would require it to supply a current of almost 300,000 Amps. A decent PP3 can probably just about manage 1 Amp, maybe?

HD moment from video

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    I won't judge the credibility of the video, but the argument that you need the 'same amount of power to fry a bike's electronics as you do to light up a fluorescent tube' is way off. You can fry electronic circuits with a petty static discharge. – Tor-Einar Jarnbjo Mar 14 '17 at 18:37
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    @Tor-EinarJarnbjo: Delicate, unshielded electronics. If a static discharge was enough to fry a bike's electronics there wouldn't be any bikes, they would be totally impractical from their electronics constantly failing. – TheBlackCat Mar 14 '17 at 19:48
  • @TheBlackCat I am not sure what you are trying to point out. Are you saying that the electronics in a cheap scooter is shielded against microwave radiation? – Tor-Einar Jarnbjo Mar 14 '17 at 21:09
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    @Tor-EinarJarnbjo: No, I am saying that the simple analog electronics in a cheap scooter are inherently less sensitive to damage and interference than sophisticated digital electronics. – TheBlackCat Mar 15 '17 at 1:21
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    You don't think the fact that everyone is wearing tin foil hats is a clue about the veracity of this scene? – DJClayworth Mar 15 '17 at 15:53

I'm going to go out on a limb and say this is plausible. The main issue is your calculations are way off. This paper Beam Control Technologies With a High-Efficiency Phased Array for Microwave Power Transmission in Japan shows your numbers are off by orders of magnitude. From that document

The efficiency of the magnetron was above 70%, and it was the cheapest available microwave device

While I don't expect you would to get anywhere near that efficiency, I'm not sure you need to. If this actually works, I believe the ignition coil is acting as a loop antenna. At 2.5GHz, the wavelength is 12cm, which would mean the ignition coil has a fairly good chance of being about the right size. To actually disable the vehicle you would only need to transmit enough energy to burn out a fuse. This link Directed Microwave Energy he describes destroying a cellphone using three magnetrons. I think using some heavy duty capacitors, you could get a fairly substantial kill range.

Feel free to let me know if I have anything wrong.

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    I didn't add it to my answer (since I couldn't find any mention of them), but if I recall when I was working with alarm systems there was an emp alarm that you could use to trip the alarm if someone was trying to kill the alarm panel, but got the sensor first. – Philip Tinney Mar 16 '17 at 8:32
  • With modern electronics you only need a milliamp or so to disrupt the electronic controller for the bike. – Daniel R Hicks Jun 3 '20 at 17:42

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