how can i turn a magnetron from a microwave into a herf gun?

hello
i am feeling particularily creative at the moment and would like to go down to the beach and pick coconuts from the coconut trees, using a herf ray , in which i would blow up the coconuts with the microwaves being emmited from the magnetron.
what i want to know though, as it seems to be missing from every single webpage which mentions the construction of a herf ray using a magnetron is, how exactly would i set up the magnetron so that it would create a directional beam capable of frying a coconut abbout 10-30m off the ground?

i have seen this being done by a guy on the beach before, making the coconuts explode using a herf ray,
when i asked this person how he was doing it he simply said that he was using a microwave gun made from a microwave

also, i have no intension of climbing the trees to get the coconuts

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A microwave recently took apart had a schematic in it so I made it on paint just for you :)
microwave setup .jpg
One problem with this plan, power. First, the magnatron in your bomb box is nowhere near powerful enough to cool something at 10m and certainly not at 30m, most are barely powerful enough to cook something in a steel box designed to reflect the output back into the food. Second, where is the juice coming from? Microwaves have huge transformers designed to provide massive amounts of power that the cooking circuitry requires, you would need something at least as big as a car battery or a deep cycle marine battery, which in all likelihood might not last long. Thirdly, focusing of the microwave beam might be difficult but it is doable, do some research on microwave collimation (sciency term for focusing of electromagnetic waves) potentially that might get the limited output of the 1-2kW magnetron in a small enough beam to nuke coconuts at a distance.

On a parting note, don your goggles and labcoat and let one of those mad scientist laughs loose, because you're doing SCIENCE! Also you might want to be really careful with your raygun, think of it as a sort of mobile, short-range, directed EMP, and no "tests" on living things (maybe plants, there's no legislation on nuking a neighbours petunias, also wasps, it could be quite effective at eliminating them)
oldmanbeefjerky (author)  The Ideanator6 years ago
i am quite well aware of the power issue, and to let you know im using a small compact 800w generator which is remarkably silent i might add, to power the magnetron required i decide to get it portable at all (i have coconut trees in my yard as well).
also, i am well aware of the dangers of microwave radiation, thats why i have a full aluminium suit i shall ware as i blast coconuts open with my mighty cannon ontop of my quadbike on the beach, the suit though i am well aware wont protect me from direct contact with the beam, but should sheild the odd pulse that may escape due to por workmanship of the thing overall, plus i just like wearing it and sounding like some alien apocalypse heratic.

lastly, from a 800w magnetron, what would you estimate the distance at which ill be able to boil and explode the coconuts at? my dad told me of a story about how he spent 6 hours collecting coconuts and sheeling them, then leaving them in the sun for 3 hours only to have them all explode,

from what distance and how long, can i simulate a 30 second cooking in a microwave using the beam?
If you accomplish this feat, I would LOVE to sea a video, the description of your intended activities alone is incredibly amusing! Link that video to the mythbusters too, they'd have fun with it. Though, if you are completely serious, see if you can source some used radar equipment, I believe they have higher power magnetrons inside but don't quote me on that.

they do have very powerful magnetrons in them

Given that it takes me two minutes to heat a cup of water enough to make tea in my own microwave, and given that only a small portion of the beam is likely to hit the coconut even if you _do_ get it somewhat collimated..

... I find myself wondering whether you were hoaxed.


Rizingfire4 years ago
You need to put an aluminum antenna so to speak around the magnetron. I can't remember if microwave radiation waves are 4 or 6" wide but youwant it at least 4" wide at the base and maybe 6-8" in the outer end that you will point at whatever you want to microwave. You will need a high watt microwave for good results. I used a 600w one and it was pretty worthless. A 5,000w microwave magnetron will set a piece of plywood on fire from 100ft away...but I have yet to find one and the 3,000w ones I have found are $1900-$3500
It will basically be a tapered metal rectangle. or oval tube...
What you call an antenna would be a "wave guide" which is just a square or rectangular tube made of heavy guage metal to direct the beam.
Do you have a link to this alleged guy-making-coconuts-explode-with-herf-ray video? I kinda want to see it. It sounds really freaking nuts... if you'll forgive the pun. I tried searching for herf+coconut on YouTube(tm), and the weirdest thing I found was some bizarre animation set to a  techno song called "Up Butt Coconut" The following link might not be safe for work, or safe for play, or safe for living things in general. Just don't click it, because some things cannot be unseen. http://www.youtube.com/watch?v=VImAGUVd8_4

Seriously though, if you can provide a link to your exploding-coconut video, that would be very cool, and/or helpful to your query.
oldmanbeefjerky (author)  Jack A Lopez6 years ago
youd have more results ide think blowing up unripe mangoes instead, as a greek friend of mines brother built one of these, which they used on their mangoe plantation to scare off the cockatoos by blowing up the mangoes near them. they used a large magnetron operating on a sla inverter, but it definately worked, they said it could blow up pretty much any unripe fruit though, and it worked from 40 meters awya on mangoes.

anyway, if anyone does find designs for a herf gun that operates at over 20m ill give a best answer, required it actually will be able to microwave things at the distance, and not just be used as an emp for knocking out electronnical things
Did you do a YouTube search for Herf Gun? There are only a few videos related to that search term. If you shorten it to Herf (with a space at the end) you can find a few more. Still, I didn't see anything with an exploding coconut.

Also, you won't get 100% efficiency from your "herf gun" (800 W magnetron/800 W gennie), more like 50%-60%, IF you can get it to work at all with the reduced input level without tripping the gennie's breaker.

Qa
Hey thanks for the links, Q. No exploding nuts, but there do appear to be some good homemade-microwave-gun videos out there.   

Regarding power and efficiency, I'm not one of the nuts who actually wants to build one of these.  I think I'd rather just see the video(s) if any exist.

On closer reading of the original poster's question, I realized the OP is claiming to have seen exploding coconuts IRL (in real life), and moreover OP conducted an informal interview with "guy on the beach", creator of the alleged microwave gun and destroyer of coconuts.

Yeah. Basically I did not read the question closely, and incorrectly assumed the events in question were witnessed in a YouTube video.   Somebody sees a video, then asks the Instructables Answers forum, "How did they do that?"  That's the usual way it happens.  I think it was the fact that this question (allegedly) involved someone actually going outside and talking to people,  that was the part I found confusing.
;-)
Re-design6 years ago

THis photo should start you in the right direction.

Caution!  Stay behind the open end!