Let the microwaves be free

Experimenting with a broken microwave. The high voltage and magnetron still worked, so good material for microwave experiments. I cut the wave guide out so I could aim the microwaves anywhere I want to.

[@gbspikyfish]

New metric for "is it dangerous?": when Matthias says "I'd rather not be too close while this activates", it's probably dangerous.

[@spugintrntl]

There's an XKCD reference in there somewhere.

[@Don.Challenger]

More likely, in particular, it is Matthias's measure of uncertainty that has gone way up and therefore due to that the suspected level of danger.

[@gbspikyfish]

@@Don.Challenger it sounds as if we're going to have to suggest the "Wandel Scale" for levels of danger.

[@V8PropaneBurner]

@@gbspikyfish exactly what I was thinking. Like the Scoville rating ⚡

[@MSB3000]

If Matthias says it's dangerous, I'm already driving in the opposite direction.

[@TailRecursion]

I never knew that slightly unhinged electronics experiments with Matthias was something I needed in my life

[@E1nsty]

haha unhinged because he removed the oven door from its hinges

[@ccoder4953]

The question is does he turn into Canadian Styropyro? Not that I'd be complaining or anything.

[@tallswede80]

claiming that something is "unhinged" is not an argument.

[@Don.Challenger]

"slightly unhinged electronics experiments" albeit well clamped up. You can always assume that in Matthias's lair and laboratory spring clamps are a free resource.

[@dansw0rkshop]

You needed it!

[@danielesimonazzi4875]

Hi, I work with industrial microwave systems based on the magnetron. When you keep the magnetron waveguide open you have a significant part of the EM wave reflected back into the magnetron due to an impedance mismatch. It is the analog of a short circuit and I think it is the reason why the EM field is weaker than you expect. Some CST simulation would do the job

[@matthiasrandomstuff2221]

I was hoping the wave guide itself would help match the impedance, as opposed to a magnetron on its own. So perhaps I should shape it more like a horn to help match the impedance?

[@Basement-Science]

@@matthiasrandomstuff2221 It's probably best to leave it as is. This shape will still form a decent beam, but if you change it, it probably wont anymore.

[@danielesimonazzi4875]

@@matthiasrandomstuff2221 I work on the power supply side so I cannot precisely quantify it the amount of reflected power. It is something magnetron suppliers warn us about since it results in its overheating. If you look for your magnetron datasheet it should come with the maximum acceptable VSWR: a measure of the energy that is kept in the waveguide in the form of stationary wave.

[@linuxguy1199]

@@matthiasrandomstuff2221 RF guy here / ham radio operator who plays around some at 10GHz. A horn with a 37 degree taper would be best, I would make it at least 1/2 wavelength long in the direction of the guide, so about 6mm, a longer horn is better but exceeding 1/2 a wavelength is too much (look at standard gain horns for some inspiration). Doing that will far exceed the original VSWR of the original microwave's waveguide to "cooking area" transistion. No simulations are needed for this, people have been designing waveguide with pen and paper for years. You've gotta realize the VSWR of the direct transition into the microwaves oven "cooking area" is probably 2 to 3:1, which is awful to say the least. If you build a linearly tapered horn with some foil you can easily achieve 1.3-1.8:1, optimally you want 1:1 but unless you machine / plate your own horn you won't be getting that. On a side note, metal plating or foil wrapping a 3D printed an optimally tapered WG horn is certainly a possibility and in a scenario like that you probably could achieve extremely good VSWR. VSWR is a shorthand way of measuring how well two impedances are matched, but it ranges from infinite (horrible) to 1 (amazing).

[@nancy2568]

I repair residential microwaves (sometimes, they are mostly throw away items), and I have worked on commercial microwaves in restaurants, having attended countless schools on microwaves, I noted that difference in the capacitor size on microwaves. I asked Amana service about it and they said " the size of the capacitor is inversely proportional to the cavity size" I.E. the larger the cavity, the smaller the mf value of the capacitor. I watched as Jamie from mythbusters attempted to put together a "super microwave" by combining for HV circuits to a very small box, but nothing happened, Even I could tell the box he made was too small for the microwave em band to properly form. Random stuff here at least did it right, but if you want to play with the waveguide outside of the microwave cavity, try using a smaller capacitor, like a 0.75 mf, you might get better results. I am also glad to see that you kept your kids away from the high power experiments, I was cringing with them going at the microwave, those things are dangerous if you don't know what you're doing.

[@dakiloth]

"I went through my neighbours trash and taught my kids how to make a death ray"

[@frollard]

Would love to see glass versus hot glass. Glass is microwave transparent. Hot glass (low glowing cherry hot) actually absorbs microwaves, and it forms a cascading chain reaction. Try heating a bottle with a torch until it's quite hot, then put that in the liberator.

[@tsalVlog]

Boost this signal. criticality in glass is amazing to see, even if isn't actually nuclear.

[@unmanaged]

coat the glass with some silicon carbide grit and it will get crazy hot fast ....

[@djmips]

I think he said something about not wanting glass shrapnel ;-)

[@darkfur18]

@@djmips sounds to me like he'd have more to worry about from glass splatter

[@daveduncan9005]

I love how Matthias talks about his dangerous experiments like I talk about getting milk from the store. So ho hum. I wish I had had a Physics teacher like Matthias.

[@puttster2003]

I love that you include your children in this project. Teaching how to assess and manage risk, amongst other things 👍

[@yashsvidixit7169]

@@SunriseLAW great upbringing.

[@clydedecker765]

Microwave guides take on a whole science by themselves. I worked DEWLINE Radars. Those have very large waveguides to the antenna from the magnetron. And then there's the horn inside the circular antenna dish to direct and collect the signals... That bump in the guide you have would serve to disperse the concentration of the waves so they aren't so concentrated when they get inside the box. The waves travel best when properly tuned to the particular frequency of the magnetron and in certain sizes in relation the the wave's size.

[@toms.3977]

I love your experiments. So entertaining. Thanks Matthias!

[@shookings]

Matthias after the bulbs blow up: "Oh, I'm never gonna get tired of this"

[@afourtrackmind]

You’ve got a wonderful knack for cutting to the chase. I love how you explain things. Thanks.

[@rob3125]

Matthias never disappoint when it comes to electrical safety, and now also microwave safety.

[@SuperDavidEF]

We need a collab with Electroboom.

[@rob3125]

They are both horrible at working with mains electricity.

[@thunderstruck1078]

I love these experiments of yours.

[@altronixvideo]

As a kid I used to put thermal printing paper (old fax machine paper) inside a microwave to view the wave patterns/hotspots.

[@JimWhitaker]

I shall now go to the kitchen and try that out. Printer paper and a glass of water (for ballast).

[@realsolarcars]

Because of the voltage doubler circuit the magnetron operates with less than 50% duty cycle. That leaves plenty of airtime for the pings to get through. But the more I think about it, the microwave signal might only affect one or two of the OFDM carriers at a time. That might cause only occasional packet errors.

[@classicbandgeek]

Thank you for embracing the chaos of modern KZbin and contributing to it, Matthias

[@bobafetting6373]

Utterly deranged and also dangerous in the wrong hands (i.e. mine). I LOVE it!!

[@PeteLewisWoodwork]

I mean, that's why I love watching your videos. From the mundane to the ridiculous, they are all entertaining.

[@Metroid-rg9pn]

That slinky was an awesome visual representation!

[@ce.nz0]

I suspect the reason why the wifi kept working was that the magnetron's duty cycle is never more than 50% due to the voltage doubler. That leaves plenty of time for transmission errors to be corrected at the link layer. Now, what you gotta do next is put two MOTs in series and full-wave rectify the output to run the magnetron at 100% duty. You might want a longer extension cord for that one 🙃

[@superdau]

The magnetron is running on DC. That's what the diode and capacitor are for. It is emitting radiowaves constantly.

[@wesleyson21]

@@superdau The diode and cap only give half-wave rectification so not really a smooth DC supply. The supply voltage still falls to 0 volts when the AC switches cycles because that cap isn't big enough to maintain voltage during the whole cycle.

[@jasonharrison25]

@@superdau more like pulsed DC

[@heinrichhein2605]

@@superdau no it is running modulated otherwise you would have a horrific power factor etc.

[@blue5659]

​@@superdau wtf fam why use big boii vocab with smoll boii logic?? You know what a magnetron is but dont know what a half wave rectifier is???

[@timhumphries479]

Really happy i discovered your channel!

[@NotRexButCaesar]

It is nice how simple the basic mechanism is.

[@jcost0099]

In military days, we cal'd radar transponder sets and more. We had to ensure attenuators were in place so as not to cook the guy on the bench next to you! Love your channel btw!

[@MatterLabz]

Very interesting video! I've wondered about many of these questions ever since a friend's Mom purchased the 1st microwave in our neighborhood.

[@nobuckle40]

You had me hiding behind things and I wasn't any where near the experiment! You mad scientist you! It was cool to see the egg eggsplode.

[@super8hell]

Love the static wave explanation. I am also very curious to how the "YT comment section safety officers" will respond to this video. Personally, I would think twice when directing comments at experienced engineer.

[@gorak9000]

You'd think by now the YT safety officers have moved on to fresher pastures. Matthias lives off of the safety nzzi's tears! The more they whine and moan, the happier Matthias is!

[@allencummings7564]

No safety comments that I can see

[@The2004NissanXTERRA]

"liberated microwaves" is now my favorite phrase

[@officerockstar]

Favorite quote of the video: “not suitable for dangerous experiments.”

[@Ranger_Kevin]

Nice throwback to the old youtube channel "is it a good idea to microwave this?"

[@atheron1776]

Nobody likes roasted nuts!

[@michaelkessler3813]

My grandpa was a technician during the Korean War, they used to warm up sometimes by standing in front of the microwave antennas during winter

[@windsunh2o]

Seriously? Did he ever have health problems related to that?

[@Leadvest]

Just like Lovelock's frozen hamsters!

[@sparqqling]

@@windsunh2o he still got kids

[@michaelkessler3813]

He had five healthy kids and died in his early 70s due to genetic heart issues

[@NoelBarlau]

I could watch this kind of thing all day long. Well done.

[@jstro-hobbytech]

He better hope no dust comes of that highly radioactive pink strip. The name of the chemical escapes me.

[@eh42]

For a headscratcher, map out the interlock switches. On most ovens, by design, if the door does not close properly, the switches will create a dead short across the mains just after the fuse. I'd like to understand the rationale behind that design decision! (My microwave was blowing internal fuses, and I found out that if I was "too careful" in opening/closing the door I setup the dead-short condition, which got worse as the mechanism wore out - the fuse has been replaced and the circuit rewired for less safety more reliability!)

[@L2M2K2]

I think you might have answered your own question. Maybe it is for safety. As, the partially closed door might be indicative of a mechanically broken door, leaking microwaves (and causing considerable risk depending on which which edge it leaks out from). Thus, better to blow the internal fuse than allow multiple tries. Alternatively, it is engineering laziness. The circuit diagram would tell if it is an added feature or an undesired side effect of simplest possible wiring diagram for the N safety interlocks. This would then help answer the dilemma. Good engineering or laziness.

[@caseyrevoir]

The magnetron is shut off with one switch, and if that switch fails, the second switch will blow the fuse or breaker to render the fault visible and un-ignorable (this is why you should use the stop button to prevent the arc in the switch) 12voltvids covers this frequently kzbin.info/www/bejne/opvMfnh3dsqjhtk

[@eDoc2020]

Abused switches often weld shut, not something you want to rely on in a safety circuit. The monitor switch normally doesn't carry current so the contacts don't get worn.

[@jhensjh]

Yes, 5 or 6 years ago my microwave began tripping the circuit breaker whenever the start cook button was pressed. I traced the problem to a failed switch in the door and was dumbfounded to find the switch was dead shorting the mains. I figured this had to be a rather extreme safety feature. I replaced the door switches (only one had failed) with new parts and the microwave is still working fine to this day.

[@caseyrevoir]

@@eDoc2020 This is precisely why the circuit is designed the way it is, the unit would operate with the door open. When op's door went janky they activated the shorting micro switch first instead of second. Because the first switch is likely to weld closed eventually, the second switch will short the oven, this second switch never sees a load unless the first failed. (and also may stick closed, but it don't matter, even better actually) A better microwave would sense you touching the door and command the mag off before the load on the contacts is broken.

[@jatag100]

Always interesting and fun to watch, thanks!

[@ykkfamily]

You are nutz!!!! Started laughing when the light bulbs stated exploding!!! Good job!!!!

[@jester1983]

This reminds me of when I was at Waterloo. I took "the physics of how stuff works" which was purely experimental. Used a microwave to burn CDs and light cfls, launched rockets, used a big transformer to cut cans in half, built a Reubens tube to show sine waves in flames, it was great. Don't know if I learned anything, but I had fun.

[@nicktecky55]

So, THAT's what did for Napoleon? I always wondered.

[@gorak9000]

Does the microwave burn CD's faster than 40x??

[@Impractical_Engineer]

This channel is a national treasure.

[@hector5810]

Love your videos man!

[@ilcomendante]

To have a good laugh AND learn something new. That's why you're the best man 💜

[@jplona]

When I saw that power cord with alligator clips on the other end, I was expecting some kind of ElectroBOOM stunt :-)

[@sciencoking]

"Alright, time to plug it in" _utter devastation and carnage_ "Cool, I think it still works!"

[@pt2575]

That was great ! Interesting, educational and FUN !

[@billsmith5166]

Great for the patio! It cooks your chicken and zaps your bugs. Have people sit where the ping times are normal, or you can have them sit where the ping times are really slow depending on your mood. As usual, thanks for the video!

[@jhonbus]

Alas, the wavelength is too long to zap anything but fairly large bugs! Not gonna touch mosquitos.

[@billsmith5166]

@@jhonbus Wouldn't that only be true if they were stationary?

[@blue5659]

​@@jhonbus maybe. Even if moskittos or smoller, they will be subjected to an alternating e field, which should cook them over time. But since moskittos are flying they probably wont stay in the beam cone long enuf

[@MCsCreations]

Fascinating stuff, Matthias! Thanks for sharing the experiments! 😃 Stay safe there with your family! 🖖😊

[@arkitson]

If you take the turntable out and melt some chocolate bars you can measure the wavelength from the hot spots from the standing waves. The frequency is usually written on the back of the microwave. Multiplying the wavelength and frequency you can use this to measure the speed of light. It’s a good experiment to do with kids, and they get lots of runny chocolate at the end!

[@matthiasrandomstuff2221]

The frequency is always the same, no need to measure it.

[@luvmechanix]

Adrian that's awesome

[@Farm_fab]

Matthias, I hope you plan to make a magnetic "vise" for your drill press. I'm always interested in the different ways people approach these projects.

[@jimturpin]

If you want to get a 3D representation of the RF signal in your microwave, fill a bowl with egg whites (the clear stuff, not the yoke) and then run the microwave for a few seconds at a time. It will make all sorts of patterns in the egg white along the paths of energy. Cheers!

[@callumrobertson1081]

While I'm a big fan of the videos on the main channel, the best content is definitely to be found here.

[@T1nCh0]

God I love these experiments.

[@MurrayFCohen]

Hey, Matthias. this is not about microwaves, but about RIM and the book you recommended Losing the Signal. I am about halfway through it, at the point where Apple is introducing the iPhone, and it’s taking off. This is the most fascinating and untold story of the technological breakthrough of our era. That moment in time between texting and the smart phone of today. I lived through it. I guess I was in my late 40s when it happened and I remember owning a PalmPilot and a BlackBerry. I was in a tech business at the time and everybody was talking about mobile. And I literally had absolutely no understanding of what this would become. In fact, I didn’t even believe it. How could you live without a keyboard? And you were a part of it. If you get to the end of this message, here’s a story idea: reenact your time at RIM when you guys were stationed in the bathroom, and you had a lever you pulled that flushed a toilet every time you guys eliminated a bug. That is SO Matthias Wandel! A star is born!

[@klonikFPV]

Wi-Fi is working with several tight frequency bands between 2.4 to 2.5Gh therefore could be that magnetron was operating at not exacly the same frequency.

[@E.lectricityNorth]

You're an amazing teacher!

[@LouisEmery]

WIFI routers are tuned radios. So interference from other frequencies, in this case a single frequency from the magnetron, is limited. You could taper the waveguide over many wavelengths to help the matching to free space, like a trombone bell that matches the acoustic wave to the open air.

[@johngregg5735]

Brilliant as always Maybe you can tie the microwave into your home made wasp catcher? Not as cool as your home made fan, but the bugs would be toast...

[@TesserId]

1:09 LOL, that frickin' mad scientist stuff.

[@Slugsie1]

Very cool experimentation. I think you should get a microwave emission tester, and see how it measures as various angles around the opening.

[@vmoutsop]

I like how you say at the end "The next logical thing to try" when using a directional microwave device. 😂

[@alwaysskeptical7221]

That microwave transformer is a killer. Serious stuff.

[@redmysterium]

Back in the 80 I went to see the Liberated Microwaves perform at the 9:30 club in DC.

[@DrHarryT]

A burned door safety interlock switch is a common failure because of opening the door while the microwave is operating. The cure for this mode of failure is to ALWAYS press the Stop/Cancel button before opening the door while the microwave is operating.

[@Traderjoe]

Endlessly interesting!

[@50shadesofbeige88]

Just looking at this makes me nervous 😂 good work!

[@PJSproductions97]

It's like "is it a good idea to microwave this?" Never stopped.

[@nemmrrc]

This one is right up there with the self-propelled scaffold.

[@JonnyDIY]

I feel like I'm watching the Origin Story of how "Microwave Man" was first created 🤣💕👏👍

[@rabbitez]

I was hoping you were going to fill the glass with corn kernels to make a sort of popcorn fountain

[@djmips]

next time

[@sdavidleigh6642]

Can't wait for the next mad scientist experiment. Bravo

[@pootispiker2866]

Everyone's bluetooth within a 3 mile radius cut out while he was making this video

[@EEGworld]

Am I the only one who is getting max 480p resolution? great video!

[@matthiasburger2315]

As a physics teacher I am delighted... unfortunately I would get in trouble doing such experiments in class.

[@sl6891]

THE Matthiases 😊 coopration again?

[@marcoschwanenberger3127]

Awesome! Little bit of knowledge: The MythBusters actually tried what would happen if a "person" would be exposed to a ton of open microwaves. They put like 20 Microwaves in a small room, opened the doors (bridged the door contacts so they would turn on) and hung a pig in the middle of it. It didn't even get warm at all - even after they covered the walls and ceiling with aluminum foil to try and keep more of the microwaves inside the room. So for the safety folks: No, having this one Magnetron in the open is not going to boil Matthias alive!

[@michaeltempsch5282]

The output of the transformer, on the other hand...

[@esepecesito]

Best video ever!!! Laughed a lot.

[@grugbug4313]

Solid! Top KEK! Peace be with you.

[@daylen577]

Our microwave is a newer one that doesn't have a rotating platform, but nowhere in the instructions does it say where your food should be for even heating. Turns out it's a lot less bad when you put the metal rack roughly 2/3rds down from the top, but that goes against everything I've been taught so I didn't try it at first as we always took the metal rack out when using the microwave.

[@Gunbudder]

why are microwaves simultaneously so fun and so lethal?? I have to guess that a microwave transformer has probably claimed the most lives in recent years of DIY electronics projects (mostly through those lichtenburg things)

[@heinrichhein2605]

they are not really that lethal, you can get deep burns and the electrical shock hazard is big

[@BariumCobaltNitrog3n]

TikTok challenges are far deadlier

[@orange13]

great tutorial

[@dakiloth]

Interesting fact, industrial kitchen microwaves don't rotate the food. They rotate a reflector to move the hotspots instead.

[@Basement-Science]

@@XenoWiz no it's not. Every microwave has a wave guide, that's just the part Matthias cut out of the microwave case. A moving reflector basically moves the standing wave pattern instead of the food.

[@gorak9000]

Some of them have 2 magnetrons too, one that feeds in from the top, and another one that feeds in from the bottom. It helps give better coverage, and shortens the time required too. I have a couple Panasonic commercial microwaves in my garage.

[@dakiloth]

@Xeno I thought waveguides were hollow metal tubes

[@Basement-Science]

@@gorak9000 I imagine the main reason they're using 2 magnetrons is to avoid building a custom, bigger one instead. Consumer-sized Magnetrons are very mass-produced and probably cheaper. Then the placement is just what makes sense, mostly.

[@gorak9000]

@@dakiloth That's exactly what waveguides are - hollow rectangular (or oval) tubes that convey RF energy. Usually used for high power or high frequency applications where the losses in coax cable would be too great.

[@automaticgainsaying]

All I kept thinking throughout this video is "What will Matthias' superhero name be after the lab accident?" ... Perhaps when one of those rogue rodents escapes one of his mazes and tips over the magnetron/wave-guide ... My first choice is "Amazing Man!" (Geargantuan, Pantoman, Woodias, ???) His superpowers will be: he can turn anything into wood and run diagnostics ad infinitum. His Kryptonite would "pocket holes" and "annoying comments". His closing sequence would be jumping onto whatever he has made into wood. His catch phrase/moto (still deciding from): 1. "Gears-wood-work" 2. "Cool, I think it still works" 3. 4. "I'd rather not be too close" 5. "I wonder what will happen if ...?"

[@BarneySaysHi]

This is the more extreme version of "Is it a good idea to microwave this?"

[@lorenzo42p]

still closer than I'd feel comfortable. you can't feel your organs cooking.

[@howder1951]

They blowed up good, they blowed up real good!

[@PlasmaFreak]

I’d be interested in seeing how changing the waveguide to a feed horn would make your beam narrow. Also wonder if you could somehow make this into a phased array

[@severs1966]

It's nice to see that it's not just ElectroBOOM channel that does insanely dangerous experiments.

[@richardl6751]

Hopefully Matthias watches ElectroBOOM's channel to see what NOT to do.😆

[@breezetixhv]

me included lmao, kind of

[@MRrwmac]

Always great to see your experiments. How about a video of you teaching just a little bit of science to the kids?

[@johnford7847]

Interesting. Although I was flinching a bit when you started firing it up outside the cabinet.

[@georgelewisray]

SCBF :: Science Can Be Fun . . . . . . once again your have educated us while making us smile ! thanks for what you do . . . .

[@kasbakgaming]

Very interesting stuff. I wonder how the liberated microwaves might affect drying out a piece of wood? Would be interesting to get a moisture content reading on a piece before and after.

[@anullhandle]

Heatwave used to be a manufacturer of rf/vacuum kiln dryers.

[@jamesgreen3831]

Love it

[@hansangb]

LOL. I thought you were going to recreate the original discovery of the microwave! Glad you didn't! :)

[@scotthansen400]

Didn't expect to see this turn into an ElectroBOOM video.

[@gorak9000]

I didn't see anything go boom in this video... ElectroBOOM blows stuff up (or more accurately shorts the line voltage usually) to get views!

[@peter2327]

I laughed out loud when I saw the power cable with the clamps.

[@ArcaneTinker]

There's two really lovely donut magnets in that magnetron. Easy to remove too!

[@tomlogan2102]

I just keep asking myself, how did this guy get so smart? I find myself laughing with glee.

[@samTollefson]

Let's start a movement, "Free the Microwaves!"

[@redsquirrelftw]

that's some fun stuff lol. Would be interesting to see how much the wave spread but it would be kinda an expensive experiment. Essentially would need to create a wall of CFL bulbs and see how many of them light up.

[@bborkzilla]

Yes - those safety switches on the door fail very easily, since they are switching the entire current of the magnetron. They are also really, really cheaply made. I have 20 year old microwave that failed a few years after I bought it new. Replacing those switches with real Microswitches has kept it going perfectly.

[@Graham_Langley]

They can also get knocked out of adjustment or have their mounting points break - had examples of both on other people's microwaves I've been asked to see if I could fix.

[@Gunbudder]

0:21 lol! i love that you still call it a condenser, its very folksy

[@fabricio.ferrari]

Cooool experiments and nice physic lessons.

[@alphonsereitz]

Keep up the good videos!

[@1bigapple2]

I had that same microwave oven with the same failure - a 75 cent micro switch went south. Such a good solid oven lost to a cheap switch, but I did get a cool transformer out of it (& a large cap)😊

[@jamescollier3]

yup. me too

[@Basement-Science]

You could just buy a replacement switch. They're not that specialized.

[@1bigapple2]

I had the same failure - a $0.45 micro switch failed. By the time it was disassembled enough to trace down the switch it was too late. Also being 12 years old, something else was likely ready to fail. I did get a great transformer and a “Killer” capacitor out of it though.

[@kreynolds1123]

I suspect that with all the standing waves, some power is reflected back into the magnetron. It might be interesting to know if a cavity could be built to reflect most of it back in phase, and maybe reduce the magnetron's power consumption. Untill something is inserted in the cavity that absorbes it.