Battery-Powered Magnetron

In this video I'll explain how a Magnetron works, collect some current/voltage numbers on a typical household magnetron from a microwave oven, and show how to power one off a 12V battery.
Typical DIY magnetron videos only show how to remove the transmitter from the microwave oven and run it with its original circuitry off mains power. Here, I'm basically building a high frequency inverter circuit to run off DC so that the entire device is portable. To do this, I have a ZVS oscillator driving a transformer primary, and the secondary coil is connected to a voltage doubler / rectifier to provide about 3.6 kV DC. There's also a low voltage / high current winding on the transformer to provide power for the Magnetron cathode filament.
One of the biggest frustrations of this project was trying to deliver enough current to the Magnetron cathode filament with my ZVS flyback transformer. It took a lot of messing around until i discovered that the filament has some RF chokes in series with it, giving it about 2.8 uH of inductance. At 40 KHz, this inductance resulted in too much impedance for enough current to flow. Fortunately, the fix was as simple as adding about 7 uF of capacitance in series with the filament to cancel out the inductive reactance.
With a proper waveguide, the microwaves could theoretically be focused into a relatively narrow beam, due to their small wavelength. However, that's a project in and of itself, which I'm not going to tackle in this video.
Output power of the 12V circuit in this video is only around 50-60W, but it can easily be increased by using a larger capacitor value in series with the voltage doubler on the transformer output. Be sure to use metal shielding around yourself and valuable electronics if you do this.
Schematic Link:
drive.google.com/file/d/1MyQg...
Music Used:
Local Forecast - Elevator
Kevin MacLeod - Bossa Antigua
Kevin MacLeod - Lobby Time
Topher Mohr and Alex Elena - Fortaleza

[@AsymptoteInverse]

I'd like to take just a moment to appreciate that this is the first time I actually feel like I understand how a magnetron works.

[@chimerahitman]

True, always baffled me.

[@BurnerJones]

Same, this has been the best explanation I have ever seen.

[@wbeaty]

During WW2, when the UK paperwork arrived at MIT days before the UK inventors did, the physics group tried to figure out the magnetron from first principles. I.I. Rabi got it right, saying "why, this is nothing but a whistle!" Others chimed in: "Suuure Rabi, now please explain how a whistle works!" (Yep, it's just some beer bottles, with wind blowing across the openings, but using electrons rather than air. Well, more like a many-kilowatts air-raid siren, which can set fires in acoustic absorber materials placed nearby.)

[@wbeaty]

@@BurnerJones The difference is, he gets it right. Every textbook I've ever seen gets it wrong, by claiming that it uses resonant microwave cavities (halfwave in diameter). No, they're way smaller than GHz half-wave. Instead, they're just like he says: one-turn nH inductors, in parallel with pF capacitors. Tank circuits! (An LC circuit can be far, far smaller than one wavelength.) The rotating electron-beam looks like a spinning wagon-wheel, and it zaps each little capacitor-gap as it zips by, to keep up the CW ringing.

[@BurnerJones]

@@wbeaty It took me a moment but I knew I recognized your name. A friend sent me your website a few weeks ago and I've been reading your articles before bed. Despite being an electronics hobbyist for a long time there were a number of things that didn't make sense to me that do now - thank you for that

[@zyeborm]

Just to mention it. One of the big risks with this kinda RF is it can heat your corneas, you don't have the ability to feel heat there so you won't know it's happening. Once they get above ~40C or so the protein that makes up the lens of your eye will cook and at best you will lose the ability to focus your eyes. Generally you will get cataracts as well fairly rapidly after. This isn't the kinda stuff to muck around with casually.

[@cebruthius]

THIS should be displayed in a card for 10 seconds before a video like this. Or at least the channel owner should pin this.

[@paulmaxwell8851]

I agree. I lost my vision to cataracts at a fairly young age due to lifelong exposure to ultraviolet, radio waves, microwaves and x-radiation while tinkering in my basement. It was no fun going blind. I lost the ability to drive a vehicle and my wife had to take over. I even lost the ability to read a magazine or work online. It was truly awful. In the end, I was eventually able to get cataract surgery and life is pretty good now, although I never regained the close-up vision I once had. Tinkering and experimenting is fun, but be careful, and make sure you understand the dangers!

[@user-lp3cf5yn5b]

​@@paulmaxwell8851yes. I seem to remember rf safety being covered in the technician class amateur radio tests back in the day, and not looking into waveguides or operating VHF and higher amps with covers removed was a question.

[@wbeaty]

@@paulmaxwell8851 I can SEE my own cataracts, with DIY cataract-viewer. Every year they're slightly bigger. To do this, look at a distant LED in a dark room, then place a powerful converging-lens over your eye. (I use the tiny lens on my swiss army knife.) The bright point LED turns into a bright disk. Any material in your eye will then cast shadows. You'll see "floaters." But if you see any apparent hunks of glass, those are incipient cataracts. A better DIY device would have an LED shining through a single optical fiber. Then place the end of the fiber within a few mm of your eye surface. Put it in a dark-painted cup, which correctly positions the fiber when the cup is against your face.

[@thomasslone1964]

yea seems like I would only play with this if I had proper shielding and something that could detect rf leakage

[@madrigo]

Ladies and gentleman, THIS is what I'm talking about. True maker video right here. Technical, but didactic. Easy to follow with basic electronics knowledge and still going WAY beyond the boring flashy stuff you see on other channels. Packed full of content, building a cool idea, troubleshooting the many challenges and still, all withing 15min. Bravo! Amazing content as always Pirate, cheers!!!

[@rodrigo_dm]

and hella funny as well!

The explanation is one of the best, I agree, but I'm missing a safety warning. There have been numerous cases of people causing themselves neural damage, or going BLIND from accidental exposure to an operating microwave oven magnetron. And it's not like the waves go in one direction, they reflect. And it generates so much crap, it's a really bad idea to run this anywhere near an urban area. And not to forget, playing with MOTs alone kills more people than any other projects you find online.

[@Enderdragon91]

​@and let's not forget the dangers of pissing off your local Ham operators with all the radio spikes up and down the spectrum you cause with an unshielded class III device! The horrors as they hunt you down and give you a stern letter or talking to!

[@NIOC630]

Do you have links to those cases? I have never seen one. @

[@pixieflitwit1516]

@@NIOC630 My instant thought is that it is a stupid idea regardless if you are a ham or not and regardless of whether or not hams might or might not hunt you down (they likely would eventually). It is a stupid idea. Good for nothing more than malicious purposes.

[@christopherleubner6633]

Ah why your transformer burned out was that when you balanced the impedance you nullified the cathode chokes that are hidden under the rear cover of the magnetron, the mismatch reflected the energy back into the magnetron and the cathode created a ready made antenna. Also the pink insulators are aluminum oxidide doped with either chromium or manganese. The BeO version is bright white and AFAIK the only commercially made oven magnetron that have those are super high power industrial ones or those from early 70's microwave ovens made by Amana.❤

[@felipel.r.637]

This comment deserves a pin!

[@nathanieljames7462]

why does stack exchange say BeO ceramic magnetrons are pink then?

[@coler154]

@@nathanieljames7462 its better to assume it is and treat it as such.

[@nathanieljames7462]

@@coler154 Agreed.

[@theterribleanimator1793]

@@nathanieljames7462 Aluminum oxide mixed with chromium will generate a pink solid. Those are a packet of microscopic sinthetic rubies. Berilium oxide is just pure white.

[@christophertelford]

Exposure to an unshielded magnetron can result in permanent blindness pretty quickly. In the sense that a little exposure can produce a lot of damage. But you won't necessarily realise until a day or two afterwards. A friend of a friend lost 40% of their vision doing this. They were fine straight afterwards and then their vision went cloudy the next day. They didn't recover.

[@colibrizzonnzzo]

¿Como me puedo proteger? Algún traje especial o gafas?

[@aaejaebrown5889]

@@colibrizzonnzzo don't mess with it

[@kyonsmith5203]

That sounds more like damage from lasers, not magnetrons.

[@HoorGuvLabs]

​@@kyonsmith5203 it can cook your eyeballs to medium rare

[@solarsynapse]

WiFi is the same frequency and can do the same thing at high power and close range or lower power for a prolonged time. Don't have a WiFi router at eye level on your desk shelf!!! Some public places install large (As large as 5 feet.) antennas behind walls and ceilings to have good coverage in large areas. I know because I have installed them and questioned the safety. I was told that nobody cares as long as the signal is good. You could be sitting right beside one of the walls. If your back is to the wall, your body will absorb it. If you are facing it, your eyes are being damaged and you don't even feel it.

[@mhyzon1]

I have a Masters in physics. I have taken I don’t know how many electromagnetism courses. This is the first explanation of a magnetron that has made sense.

[@Immadeus]

I mean its physics, it doesn't usually make sense when you learn it, it only makes sense when you use and apply the concepts yourself

[@ihtsarl9115]

yip me too I have M.S Electrical Engineering and admit that he very well fed us the theory with a spoon.

[@thomasthecrunkengine3512]

“Curse this autism of mine.” I FELT THAT SHIT

[@fun-wi9ke]

Being autistic isn't a bad thing

[@AlexanderBurgers]

13:35 can be beryllium oxide or aluminium oxide. Although given the price of beryllium v/s the price of the whole microwave appliance, I'd say the chance of it being beryllium is *very* low, but it's always good to err on the side of caution if you're not sure. Now if you were disassembling megawatt military radar systems...

[@thunderlord1263]

Berrylium is white whilst aluminium oxide is pink most microwaves recently built use aluminum oxide, its cheaper and safer.

[@T3sl4]

@@thunderlord1263 Cool fact, pink aluminum oxide is basically polycrystalline ruby -- the color is chromium doping.

[@christopherleubner6633]

Yup they add manganese or chromium to the aluminum oxide to make it pink so that they will know which is which at the end of life.❤

[@TiSapph]

There's almost definitely no beryllium oxide in consumer microwaves. Too expensive and not necessary. The pink ones are alumina with a little bit of chromium to improve its mechanical properties. The dust of that is still bad to breathe, like with any ceramic dust particles. But at least it won't immediately give you berylliosis and turbocancer or something

[@SeanBZA]

@@TiSapph Yes true, you only will use the beryllium oxide for the absolute best thermal performance, where price is not an option. not on a cheap $40 consumer grade microwave, where the OEM who made it in China only had a $10 budget to assemble it, make all the cavity and case, and ship it to the port, and still expect to make a few cents profit. That big a chunk of beryllium oxide would be more than $40 alone, right from the manufacturer. Plus it will be white, though some are marked with a pink stripe to identify them, though not all are marked, just the part number is.

[@icghost2]

Something I rarely see mentioned (and occasionally not noted on the component itself) - the white plastic oval connector on the magnetron is actually a 15kv DC capacitor. Yup. I dont know if it routinely includes an integrated discharge resistor (with mgf variations i suppose its best to assume it doesnt unless you can confirm otherwise), but standard microwave tinkering rules apply - use caution! Obviously this can throw math when adding/subtracting capacitance and should be factored into resonance/tank circuit calculations and dont overlook these when salvaging components. Many thanks for the vids - I definitely appreciate a similarly twisted sense of curiosity, particularly when its going first lol

[@MiguelDeMarchena]

Give the next transformer and voltage multiplier a generous coat of epoxy resin to avoid the (13:51) issue. For all the idea it is a masterpiece of ingenuity.

[@eDoc2020]

I'm surprised more people haven't corrected you yet, but when a vacuum tube's grid is at zero volts the current is not cut off. To cut off the electron flow you need a negative voltage. For an anecdote, I was working on a guitar amplifier with poor contact to the output tube's grid pin and in less than a minute the anode started to glow red due to the uncontrolled current.

[@Timey]

It'd be interesting to see if you can turn a microwave magetron into radar. Seeing how the story of how microwaves were made is cause some guy was messing with radar when it melted the chocolate in his pocket.

[@railgap]

They don't turn on and off fast enough for anything short range such as an amateur tinkerer would have available.

[@Kevin-xy2tu]

Old radars used to be like 20 meter wavelength, am sure there a consumer way of building it. We don't have to enter nanometer/millimeter wavelength to have a functioning radar. :')

[@Clancydaenlightened]

It's has been tried, the problem is how they design microwave magnetrons, the problem with using the magnetron in radar or rf transmission is that the magnetron cannot be tuned, it's physical construction incorporates it's tuning characteristics So if your magnetron operates at 2.6ghz you can't detune and get a 2.1 or 3ghz rf signal out of it And becomes unstable when trying to tune it externally

[@HA7DN]

@@Clancydaenlightened The frequency can be changed around a bit via modulating the anode current (quite possibly even more with the filament) but that is a small range.

[@christopherleubner6633]

You could do this, all you need to do is store the HV in a capacitor and dump it in with a fast switch, then use a pulse timer and a return detector, then take the time traveled and multiply by light speed to get your distance. A Gunn diode with a fast rectifier works well for the detector.

[@GerinoMorn]

Also, magnetron + waveguide = EMP gun. IIRC those exist and work perfectly well cooking all unshielded electronics at a fair distance. And small animals. I used to be obsessed with this tech couple decades ago :D

[@cerberes]

I can’t tell you how many times I wanted one pointed out the back of my car while driving on the freeway. Damn tailgaters!!

[@WhenIWasAKitten]

Yay Havana syndrome for everyone!!

[@derpinbird1180]

@@cerberes The us have experimented with this idea for crowd control and pursuit....with mixed results lol

[@siajomee]

Better save it in case it get taken down, I bet this is what powers all these military handheld anti-drone guns. Maybe not with consumer magnetrons if it has to be a rifle, not shotgun, but now it's available for everyone. In few months someone else will try it, make another video, repeat until it gets perfected and some florida man will get jailed for shooting down government/air force/uap objects

[@Minacious_Shenanigans]

Do you have a schematic anywhere? (Asking for a friend)

[@jeanesus]

One of the simplest most straight forward explanation of the working of a magnetron I've come across.

[@manitoba-op4jx]

what a wonderful and concise explanation of vacuum tubes. thank you for doing them justice

[@D4RKBRU73]

This is by far the best explanation of how a magnetron works that i have seen, well done!

[@rorypenstock1763]

This is a better explanation of how magnetrons work than any other I've seen on KZbin. At least, it works for me. Thank you!

[@andrewhaychemistry]

What a brilliant explanation of a magnetron. Best I've ever seen, thanks.

[@fredfred2363]

Totally. 👍🏻 I'd like to see his way of explaining displacement current for antenna theory.

[@user-ek3yi3en6e]

Very good description of the magnetron. The best I have seen ❤

[@arkohmay]

Fantastic video and demonstration. I achieved something similar by running a couple lithium cells into a constant current regulator for the filament, and another battery pack through a zvs circuit driving the primary of a flyback transformer from a CRT TV to lightly and port-ably power a magnetron. However, this setup doesn't allow my magnetron to run at it's conventional power so I made a car battery (power bank from lithium cells) to run an inverter. The catch is, the guts of the newer "Inverter Microwaves" was used instead so no heavy dangerous MOT or HV cap. (instead its a light inverter circuit in a flyback configuration)

[@adelinyoungmark1929]

just learned this recently, but the tube within the magnetron can be used to produce x-rays. its a vacuum tube and with a sufficiently high enough voltage it can produce x-rays, but in a cone out the front and back of the tube, rather than the side because most of the soft x-rays get blocked by the thick copper walls of the tube.

[@GeoffryGifari]

With a microwave magnetron? it won't fry the electrodes?

[@combycat]

There’s a vacuum tube in it? I thought it was just some other stuff

[@adelinyoungmark1929]

@@combycat the whole inside of the magnetron tube is under vacuum, and it can be brute forced to produce x-rays if you feed it high enough voltage. essentially the magnetron tube is a vacuum tube.

[@combycat]

@@adelinyoungmark1929 I genuinely didn’t know that. Thanks!!

[@xmlisnotaprotocol]

The filaments have 2 RFCs in the can too. That's where most of that inductance comes from. Great video

[@ElectronicsFreakEF]

Dude.. You did some real justice to explain magnetron to the audience. Awesome video!👍

[@Viper2026]

this is the most informative video i have come across regarding microwave oven magnetron operation (and I've watched a few)

[@tannerbass7146]

Remember kids, the first sign of high energy microwave exposure is blindness.

[@teresashinkansen9402]

Ive messed with high power microwaves and you definitely feel the heat effects, its actually not that different than being close to a bonfire except the heat is not just on the skin, it has a few cm of penetration. The hands and fingers is were this is more noticeable, you feel them warm but instead of feeling immediate cooling as if you removed your hand from an IR source, with microwaves (2.45GHz) feels hot for longer because your whole finger warms up instead of just the surface.

[@pizzablender]

The problem is with the eyes, as they have little means to get rid of the heat. And overheated eyeballs would not be fun, in fact, they could mean blindness.

[@PsRohrbaugh]

Oh now I want to play with high power microwaves.

[@beryllium1932]

@@pizzablender It is speculated that leakage from MOs causes some cataracts.

[@solarsynapse]

@@beryllium1932 And strong WiFi with 5 foot antennas or weak WiFi at very close range for long times like having a WiFi router on your desk shelf!!!

[@karlharvymarx2650]

Popular Mechanics or a similar magazine once had an article about someone trying to invent a system of indoor heating that used microwaves. I think you were supposed to use it like a portable heater, aim it at yourself while you watch "I Love Lucy." I don't know what problem lead the inventor to give up.

[@ihtsarl9115]

Very well presented theory of the Magnetron.Thanks for taking the time to make this video.

[@markwarburton8563]

That parting shot cracked me up! Well played, sir!

[@andersjjensen]

It's a lot harder to commit piracy in hyperspace than I initially anticipated. You need a whole lot of special gear for that! I can't wait for the episode on the actual hyperdrive, but seeing we're still sorting out the cooling of that, along with basic logistics like heating space rations, I'm guessing that's still a fair ways out. That said, a detour into weaponising the lunch box of death seems in order. Pirates don't just ask politely after all.

[@mikehorrocks2909]

Cooling off the hyperdrive? Wouldn’t it be possible to use dry ice for that?🤪

[@andersjjensen]

@@mikehorrocks2909 I'm assuming a hyper drive needs super conductors, which means cryogenic cooling is required.

[@chemicalvamp]

You didn't mention how microwaves can damage your eyes. Glad you can still see!

[@TheRailroad99]

That was one of the best explanations of a magnetron!

[@BVLVI]

Wow!!!!!!! High five man!! Awesome!!!!!! Night hawk in light level content. Yet you have far to go as far as presentation, the core of this is very concise and brilliant! This is something you should rightly be very proud of. well done

[@JohnSmith-gm4fj]

Very impressive!! Nice work! Your explanation of cavity magnetrons was much better than most everything out there.

[@NoPegs]

You've truly gone insane... Good job.

[@brianwhelehan9769]

It's truly amazing amount of things the magtromiter can be used for is mad

[@RZ-zv3jr]

Best explanation of a magnetron I've ever seen.

[@michaelmoorrees3585]

2:20 - It depends, on grid placement. If close to cathode, it will still conduct at ground, an a negative grid voltage is needed to stop the current flow. In VFD (vacuum fluorescent displays) the grid is closer to the anode, and then a positive grid voltage is needed for conduction.

[@mercury8961]

Amazing work. Includes tons of physics. Magnetron is a really interesting device. Only missing thing in the video is puspose of the beryllium. Once I searched how this thing is work and found nothing explanatory in youtube. You explained really well. I wonder whats is the power limits of this device. Can this thing amplify any RF signal?

[@AboveEmAllProduction]

This is how you make a video!! Awesome!!! Perfectly illustrated and explained.

[@Remowylliams]

You are crazy trying this without a faraday cage. Your BT and Wifi equipment deserve better. But with all the crazy stuff you've done on this channel, I will put this in B tier crazy. Cheers thanks for the video.

[@sivalley]

The reason you had trouble with filament inductance is because there are actual emi chokes on the filament leads in the lower can of the magnetron where the connections reside. Additionally only very old magnetron tubes use beryllium in the output antenna insulator bushing. Newer tubes that do use it have to be labeled from the factory as such. The pink alumina color is just from the manufacturing process. TIG welding gas lens cups are also the same pink alumina.

[@gorak9000]

But is there a good way to tell, without like one of those hand held x-ray spectroscopy scopes that can identify elements? Best to play it safe and treat them all as if they're beryllium

[@jetstreamsham4968]

If its not using beryllium then what is using in its place?

[@sivalley]

@@gorak9000 True, it's best to err on the side of caution, bit being an alarmist can backfire too

[@gorak9000]

@@jetstreamsham4968 pink alumina - aluminum oxide with a little bit of chromium, that gives it the pink color and makes it harder / more durable - aka "polycrystaline rubies". There's actually a good thread I found on eevblog, "Beryllium Oxide vs Alumina - is there a way to identify?". Seems that ALL of the pink insulators on magnetrons are alumina and not beryllium, as beryllium oxide is white, not pink - time to go smash up and breathe in the dust of that box of magnetron insulators I have been collecting in the garage... the internet has lied to me for YEARS

[@flat-earther]

@@gorak9000 hi gorak, have you become a flat earther yet?

[@tenlittleindians]

Interesting project. Perhaps the builder was unaware of 12 volt microwave ovens already being sold commercially? I got a 12 volt microwave. They were even sold at large truck stops here in the USA to be used by truckers while on the road. They come with an adapter to power them from a normal wall outlet too. They have a set of battery jumper cable style leads to connect to a 12 volt car or truck battery and these cables do get quite warm while heating up your food.

[@HomelabExtreme]

Considering it would have to pull something approaching 100A, no wonder the cables get hot.

[@wbeaty]

I had a recent version opened up. It had 250 watt MOSFET modules! 2.45 GHz as usual. Instead of an oven, this was actually a microwave plasma-lamp, used to produce daylight in "grow ops." I wonder if the truck-stop microwave ovens use transistors in place of magnetrons? The efficiency might be much higher. The size might be the same, what with massive heatsink needed. Heh, but with transistors, we could add audio modulation, and see if we hear little voices when sticking our heads into the beam. Much like Woody Norris' "sound-laser," but not blocked by wood or sheetrock walls.

[@leozendo3500]

would not be surprised if this guy got more knowledge than a phd. Not many people can explain the magnetron so well while having the civil/mechanical engineering background on hvac

[@silentvoiceinthedark5665]

Your speech pattern is perfectly synced to my brain. I wish all people spoke the way your do.

[@edgeeffect]

I'd love to see you do something about high level infrasound... I was always fascinated by Throbbing Gristle's research in this area but they didn't actually publish that much at all on the subject.

[@wbeaty]

@edgeeffect maybe I shouldn't say this (because maybe it might work,) but we can slow the speed of sound way down by adding mass to the air, as long as it doesn't create an absorber. Loosely-stacked paper will do this. Also, loose foams do this. If you have an ancient yellowpages, or a digikey catalog, try tapping on it with your fingertips. It goes "doonk," because the slightly-spaced paper sheets are forming a resonant acoustic chamber, where sound-velocity is extremely low. Similar things are heard when you make egg-white meringue with high-speed beaters in a bowl (you start hearing deep bass notes.) What good is this? Slower sound-waves, at constant frequency, mean smaller resonant chambers. Infrasound needs resonators, such as hundred-foot sewer pipes. With the correct "slow-wave medium," maybe we could make a 20Hz resonator which is under a meter long. To create an infrasonic whistle, next you need a "virtual trumpet horn" made of *graded* slow-wave material, to couple the outside air with the wattage from the resonator. Now go play with safer devices. Like H-bombs triggered by TNT. Ya just gotta get the topology right, no?

[@matthewellisor5835]

Outstanding video and the best basic explanation of "how a magnetron works" I've ever seen! Now, we still need the names of the fallen devices who gave up their Silicon so that we might learn. Maybe etched into a wafer?

[@haydenparsons5783]

Every video, I am even more convinced you are a mad scientist, and I am here for it

[@msmith2961]

Trust you to come up with another insane video idea! Interesting stuff as always!

[@joeofloath]

This is a really good explanation but needs an up-front safety disclaimer, the inside of microwave ovens is not a safe place for hobbyists to be sticking their fingers...

[@EZcarryINC]

does it work on honeybuns?

[@Some_Beach]

Spider-Man tier molten honeybun auto homeless targeting system

[@ShlamTorray]

If you can cook it in a microwave, you can cook it with this. You could design one special just for honeybuns "

[@robert5]

Mind blowing stuff.... Sometimes it is fun to listen and watch stuff you don't understand.... lol. i wish this guy was my neighbor. Maybe If I brought ever enough good beer and hung out with him enough I might eventually gain a tiny bit of understanding about electricity and and all these magic things strung together to make it do cool things like this.

[@hobomaster6237]

love it , youre production quality have gotten so much better than your first videos ( i love'em ) i benged watched them months ago

[@Sven_Dongle]

Is it possible the impedance mismatch of the horn is causing standing waves to be reflected back into the drive circuit and adding a resonant cavity for impedance matching might fix it? Something akin to the original mu-wave cavity coupled to the horn?

[@WizardTim]

Fantastic explanation of how a magnetron works, certainly the best I've seen. Also a pretty cool device, but how much RF power do you think it was transmitting? Seemed to me like the filament was the part doing the most heating, but I agree the RF heat is far cooler to play with.

[@AiOinc1]

You are one bad day away from being a mad scientist and I can't say just how much that makes me smile

[@ferriswhitehouse1476]

what a banger of a video. youre a hero for putting all this together

[@BiglyWeenis]

Awesome stuff! I've been wanting to make a sulfur lamp, which are powered by microwave RF! I'd be very curious to see if one could be powered with this setup.

[@ericlotze7724]

I posted another comment on this exactly pre-reading this! Open Source Sulfur Lamp HYPEEEEE

[@christopherleubner6633]

You would need a small quartz tube and fill with a little bit of sulfur and argon. The arc tubes from mercury or halide lamps work OK. You need to open it up at the filling pip and bond a silica tube to it, then add about 30mg of sulfur to it. After this fill to about 15 torr of argon and reseal the tube. The two electrodes can be used as a starter by bridging with wire. Then put the tube in a waveguide with screen in front. Initially it will glow violet then greenish white.❤

[@alexwang007]

These magnetrons behave like zener diodes where they clamp at around 5kV consistently. Constant current control would be required if you want to control the power, because they won't really transmit much below the threshold voltage. This also means you can pulse them (i.e. capacitor or PFN) and create EMP with huge power levels Edit: check comments, there are people more knowledgeable in the subject

[@Magic_Tee]

Unfortunately, the oven magnetron is not capable of delivering decent power in pulsed mode, even with a greatly increased anode voltage and replacement of magnets with stronger ones. The point is the low emissivity of the directly heated cathode and the jumps to other oscillation modes at short pumping times. There is also a moment of current limitation in saturation due to the Schottky effect. Even high-power pulsed magnetrons with an output power of 300-1000 kW with a narrow beam antenna are short-range toys. Real EMP-sources are relativistic microwave devices - vircator, MILO, gyroklystron, wiggler source, rela-BWO, ubitron, gyrotron, Cherenkov generators and so on.

[@railgap]

IT's not anything like EMP or an UWB pulse. Magnetrons are very narrowband.

[@morareduard]

I started following right about when the cryocooler series started and wanted to say that your content is really entertaining!

[@hardencryption]

Can´t wait for microwave in a box 2.0. Great content as always!

[@MrTurboturbine]

I'm curious if the Makita cordless microwave uses a small magnetron like...

[@user255]

13:37 Actually, in microwave oven magnetrons they are alumina or pink alumina. Not beryllium oxide. Radars etc might be different thing.

[@nathanieljames7462]

false.

[@user255]

@@nathanieljames7462 What is false? The beryllium myth?

[@nathanieljames7462]

@@user255 You can insist it's a myth but there's plenty enough evidence of pink BeO sintered ceramics online that I'm not going to assume everyone else is lying or misinformed about it based on a youtube comment.

[@wearyspecter]

I typically watch YT videos at twice the speed because people either speak too slowly for me or convey too little or redundant information in there speech ( commonly known as "rambling"). This is the first time in a long time where I actually have to watch at normal or x1.25 speed. Any faster and I can't keep up. I seldom leave comments, but I had to point that out. It is much appreciated to have a decent flow of information in digestible chunks for one's brain. Also, I like the humour.

[@NHOrus]

Man, you are very mad engineer. In the best possible way.

[@waifulhu9898]

as for the directional cone, i think it might work better if you directed the other side of the magnatrons emission into an angled cavity so that it cancels it out this is instead of reflecting it down the main cone for emissions since the overlapping microwaves can cause interference issues with each other ill admit im not an expert so i dont know the depth or how and why but it might be something good to look into for the next video in the series, i had a lot of fun myself trying to make a microwave 'gun' a few years ago and was doing something similar

[@railgap]

"I'll admit I'm no expert" - no need, your other words made no damn sense anyhow.

[@waifulhu9898]

@@railgap

[@EvilElmooo]

That ceramic actually isnt beryllium, use of beryllium in such appliances is prohibited by beryllium regulations. And even if it was used, such appliances have to have warnings

[@AlexanderBurgers]

also have you seeeen the price of beryllium? No way anyone would put that in a $100 appliance.

[@EvilElmooo]

@@AlexanderBurgers exactly

[@radishhat5736]

If it's an older microwave, it''s probably beryllium, also you don't need to have warnings on that kind of stuff because noone is going to reasonably get acess to it unless you tear apart a microwave. could also be aluminum oxide since that's cheaper but it kinda depends on the source of the component.

[@EvilElmooo]

@@radishhat5736 idk if really old (20y and more) microwaves had berylium inside but this one definitely isnt old magnetron. Warnings are also for classified repair personnel so warnings of devices containing berylium are as important as high voltage warnings, also datasheets have to tell you that the device contains berylium (for example old hemts)

[@en2oh]

great video! What is confirmed is the relationship between microwave exposure and cataracts.

[@WarkWarbly]

This was really fun to watch. Hopefully you had a lot of fun making this project and the video. Also... You're one step closer to a maser.

[@jeffrydiamond]

Great lesson! Thank you and thank you for sharing the schematic.

[@specialservicesequipment393]

Nice! Love the filament impedance correction.

[@stevecann3394]

Best magnetron explanaion ever. Very cool gadget 👍😀

[@gertbenade3082]

I wasn't a subscriber before this - but now I am fully rectified! Great project with perfect technical detail, explanations and just enough safety warnings... Thanks Pirate! Keep up the good work!⚡⚡⚡ Oh: Might I just add that taking this specially packed lunchbox through an airport terminal might get someone suspicious! (Now where is that Hello Kitty box I had lying around.... 😎)

[@RD-cw9ik]

Thanks for a great informative and technical video.

[@cazadordetormentasmendoza7258]

I'm waiting for the waveguide section, or at least the theory. I have been trying to make a microwave waveguide for years. Thank you.

[@beansontoast9323]

10/10 Beans, This was a great breakdown.

[@WagTsX]

immediately subscribed, what an underrated channel

[@AuTo69420]

I love your videos particularly because you say "If you want to try this yourself." You're damn right I do.

[@MarcelSchr]

I love the style of the video, good job😁

[@3ffrige]

This is like the safest project ever on youtube

[@vacantspace333]

You melted my brain with this thing bro

[@themanhimself3]

This guy is badass. Great video man.

[@mbainrot]

omg i have another DIY project to have a crack at now 😅 Thank you thou for the indepth and detailed explaination. Esp with the capacitance bit, that'll be handy for making a mains powered microwave run on 12 volts

[@gyrogearloose1345]

Very interesting and exciting! I won't be doing this myself, and please may I remind everybody - DANGER! What will be extremely interesting - High Power Infrasound !!! Hope you will do it Mr Pirate. Many thanks!

[@inductor1.77]

After I saw you wind the transformer I thought to myself "he better pot that thing in epoxy" lol I love high voltage but its hard to keep anything I make with it from burning out after a while. Although epoxy has bubbles and Ive still had things arc over that way. Dipping it in lacquer a few times and then epoxy helps a bit because the lacquer works its way in a bit better. Candle wax is cheap quick and easy and works surprisingly well.

[@vne5195]

Remember the important rule from the amateur radio test: "Never gaze into the waveguide."

[@ppentertainment2351]

Great stuff. Makes me remember my electronics course material.

[@SailingBritaly]

Your subtle truth bombs are the best part of these (excellent) videos. I understand the line you're walking, and you do it beautifully, while maintaining the ability to keep your reach. Well played mate, Chris 👍

[@testpilotmafia862]

If you have a vacuum chamber you can pot the secondary in epoxy, those HV pie windings looked great.

[@marcdraco2189]

Learned loads, thanks man!

[@xntumrfo9ivrnwf]

Finally back to the high voltage stuff!

[@virtualizeeverything]

I have learned more from your videos then I did in High School

[@Vibraza]

Brilliant content like always

[@taylorsutherland6973]

Wow, this is fantastic! Thanks for sacrificing all your WiFi devices for our (and your) entertainment!

[@theGraphicAutist]

damn, u explained everything so perfectly and thoroughly! this is awesome great video! still waiting for success on ur garage cryocooler, cuz i wanna build one! keep it up

[@SumNumber]

I was wondering about the wave guide from the beginning . You could cast some aluminum with a mount at the base and an extended tube to try and isolate the wave a little better and protect yourself a little better . Scary stuff ! Thanks for the share. :O)

[@wolf1066]

Less than a minute in, thinking "this is hysterical", liked and went to subscribe - only to discover I'd already subscribed!

[@gabrielalmeida5047]

This video is awesome, i'd love to see the equations behind those numbers tho.

[@Chems7308]

Very very good explanation

[@theworldrealm72]

Very informative, very interesting, and very well done. Thank you. I liked the outro a lot, how humor was used at the same time as it holds serious truth to it. Every now and then when I watch things like that I start to wonder if things like the mobile phone towers nearby are too nearby and hazardous to all the people in the surrounding area. Especially those that have their apartments from just 20/30/40/50 feet below it, as it's placed on the roof of the tall building they are living in. I remember a few years ago, well maybe a decade or something like that, watching a documentary which was about a neighborhood directly below some high power lines, where the residents claimed that every family had experienced several cancer-related deaths throughout the entire neighborhood because of the power lines above them. I think it was called something like the extinct neighborhood or the dying neighborhood or something along those lines. And if it really is that dangerous, then why would they continue building cell towers right above people's heads. I know they are two different things, but they are both claimed to be very dangerous to be around, and I know that people who are working with those things don't dare to approach them before they are shut down.

[@UCSsJ54o4kNA6qfcIBROxiDA]

your videos are great!! your take on infrasound would be super interesting.