Since microwave ovens were invented as an outgrowth of radar technology, is it possible to build a radar using some of the components of a microwave oven?

Theoretically yes. But it would take a lot of effort and parts. So it's not really worth it.

You have to hear as well as you transmit, and the transmitter is made to cook food... not send signals out to 'listen to'  so... yea, but not easily.

they did the opposite on Futurama

I was thinking the oven parts, some kind of antenna, ( satellite dish?) and then some kind of reciever.

I haven't the foggiest idea how to actually build it since installing a car radio is about as involved in electronics as I get, But was wondering how powerful even though it would be crude, it would be.

Don't do it....your wife will be pissed.

Really pissed.

Hmm, I have given this some thought as well.  





I live near an airfield, and I always wanted to take some magnetrons and make the planes that buzz my house drop flares.  







So, tag for information.



ETA: one of my co-workers took our Thermal Imaging Camera out one night and found some Apache helicopters flying into base in formation.  He took a peek at them, forgetting that the device has a laser built into it (called a laser pyrometer).  The birds scattered, as it set off some warning siren in them. )

2450 MHz. Bye Bye wireless Lan

She don't need a microwave to make sammiches.

Place a magnetron in a properly tuned cavity, and you'll start moving in the right direction.

Then modulate it and look for reflections and ...

It seems anyone with a good understanding of electronics and radio equipment could do it.

Leaves me out, but maybe I could make something to mess with the mexicans next door that play that rotchy crotchy music.

It would probably be easier to start from scratch.

Holy Crap



"The NWS transmits at 750,000 watts of power for their S band"



Don't think a magnatron will put out that much.

I remember in school we used microwave transmitters and receivers in a class to demonstrate the abilities of microwaves.

I think the hardest part about building a homebrew radar system would be the computer and the cone.  The cone has to be specially designed to focus the waves and then funnel the returning waves into the receiver.

I'm an electronic engineer and one of my last company projects was building a new DME(distance measuring equipment) for aircraft.
DME operates at in the range of frequencies around 1090MHz, it's not radar but timing of the transmission and reception is very loosely somewhat similar and very complicated.

To answer your question, yes theoretically I suppose it would be possible to use the magnetron as an emitter, but it would really be impractical and I mean REALLY IMPRACTICAL to the point where I would say nobody would even attempt the design or the extreme cost of implementation to even try it.

You need one of the old ones, a "Radar Range".  

Not really.

Making a RADAR (it's an acronym, not a noun, RAdio Detection And Ranging) is an extraordinarily challenging project, and, as posted before, you'd only get part of the transmit side out of a microwave set.

Sounds like a great way to damage your own body...  Know which two parts of your body fry first?

bzzzt inverse square law.  


Now if you really managed to get cookin with electromagnatism, your brain is the first place to cook.. Full of fat and water.  You really do fry that first

Actually it's testicles and eyeballs...

I actually have part of a portable radar set from the US Navy, circa the late 1970's. When I opened it up, it still had a vacuum inside and all the vacuum tubes were good.

Now I'm thinking of finding it (probably out in the shed) and taking apart the old microwave.

Hmmm... Better not. Air force base is just two miles from my house.

I'm thinking a microwave and some ham radio parts could be canniibalized for a makeshift radar. It'd be an interesting experiment, that's for sure.

It is possible, WWII air radar used a magnetron just like a microwave has. There is a lot of other stuff that would need to be created, you would need a modulator to drive the magnetron, and a complete receiver side. In addition to the health aspects that has already been mentioned there is the legal aspect that the FCC  regulates all radio transmitters. You might be able to fool around with a transmitter that was narrow bandwidth and in a little used band. However S band units are fairly common, and microwave magnetron wide band with lots on spurious splatter signals. You probable screw up someone else radio equipment and get found out and in trouble, before you got a working radar.

2.4 ghz is a poor frequency, water absorbs it the radiation. which is why it cooks so well!

I don't know about a radar from a microwave, but you can use a radar as a microwave. I've seen a turkey cooked with a SPS-49.

I would imagine a SPS-49 could cook just about anything, and probably do it quickly as well.

Personally, never actually saw it happen though.

Interesting thread. I have a 1000w Microwave that I don't use that I have been saving for some evil design. I thought about making a microwave gun that I could point at a bag of popcorn and cook it at a distance.  I don't know enough about electronics to do such a thing really, but the idea of it sure sounds cool. Maybe it is not a good idea.

You can buy radars.

Why make one?

in theory, you could build one with parts from radio shack.

Definitely NOT a good idea.  You'd need a whole lot of knowledge on how to properly direct that energy without frying yourself.

This. Making a cooker out of RADAR equipment is much easier than the other way around.

It will be difficult to build and inaccurate unless you're already up on your electromagnetics (waveguides, antennas, microwave circuits) - and if you are up on it, you should know a better way to go.

First you'll have to gate the transmission into a pulse. The pulse duration has to be long enough to detect, but short enough that you are already listening for the reflection before it comes back. Then process the return data to resolve an approximate range. Of course, you'll have to know something about the return signal or you can easily burn up your receiver chain by reflecting from something too close (or coupling if Tx and Rx are both on). Then dealing with the goofy signal put out by the magnetron... Not worth the hassle, IMO.

Trust me, what I do every day is research in what ultimately amounts to 3-D RADAR tracking in the xxGHz range.

Yeah, not a good idea to build a directed energy weapon without knowledge of directed energy handling.

Transmission lines alone are a significant challenge in homebuilt systems in the appropriate frequency range –– good point.  Most people don't realize that above a certain frequency you simply can't connect things with wires anymore.

Don't worry, NEXRADS are optimized at 700KW
Klystrons crank more power than maggies.

DMEs operate around 1025–1150-MHz, 1090 is the aircraft xponder freq

Normally, if you can spell RADAR backwards, you're qualified!

Like Joe4567 said, you would need a modulator to transmit, plus a timing system to sync the xmitter to the rcvr, STALO, COHO, mixers, a processor (to process) the returns for the display, AFC circuits for a maggie, and a transmission line - usually waveguide tuned to the frequency, and maybe an antenna. Don't forget the multi-voltage power supplies for the individual assemblies.  Rotary joint and drive train w/ a pedestal if you want it to scan. Oh, some sort of T/R tube or circulator so you don't blow out the sensitive receiver with the first transmit pulse! Check w/ your friendly FCC people to get authorization to transmit, they may require that you have the specific bandpass filters to severely restrict spurious transmissions.

Now, if you want to ditch the mechanical antenna and digitally scan, chirp, freq hop, and really extract tgts out of the grass, gotta get a different kinda oven.




I'll crawl back into my hole now.

You ain't kidding - esp.with waveguide. If the w/g isn't constructed properly - to include the feedhorn or array, Unacceptable VSWR (reflections) will result and severely cancel the transmit signals, or create arcs which could eventually damage the equipment

As a former Navy Electronics Technician (ET), I'm just going to...

Current Active Duty ETC here...

Theoretically possible, but a bad idea as stated above. Any experimentation with high-power sources like that require a great deal of thought put into shielding, safety, and exposure levels. I actually tore up a couple of junky chinese microwaves for the magnetrons, was thinking of using them for plasma experiments.


Given the risk of cooking yourself, treat that thing as a gun. Make sure it is well shielded, and pointed in a safe direction when operating(essentially any time it is plugged in, whether switched on or not). You will require a significant amount of knowledge in the area of antenna theory and RF design and shielding. Most people don't know jack shit about that stuff at microwave frequencies(and it's a much different animal than lower frequency radio gear). The ARRL has some decent books about working with microwave communications gear, it would be a good place to start - but they are usually working with VERY low power levels.

 

sure could



im also pretty certain my brain is fried from naval radar; on a surfaced submarine the radars are just above the heads of the guys in the sail. Ive spent lots of time up there with those things on...

The only part of a microwave oven that could be put to use is the magnetron, and it's a very poor choice of a magnetron.  The HV power supply for a pulse radar that would be compatible with your magnetron would have to generate 1 microsecond wide pulses 1000 times a second with a voltage of -4KV - that's negative 4000 volts.  The pulse forming network parts and HV switching tubes required for this are not readily available, even as surplus parts.

The RF output from a microwave oven is not remotely close to being usable for range and bearing detection.  It's essentially useful only for cooking food, heating things up, and broadband jamming of other services in the same frequency range.  Take the door off, fiddle with the door interlock switches so it will transmit, aim at the airport or aircraft in the area, wait for The Man to come crashing through your door looking at you through the sights of an AR or HK sub gun.  Have fun!

The waveguide and antenna construction would be a difficult task.  It gets really complicated if you try to use the same waveguide and antenna for both transmit and receive.  The receive waveguide path has to be electrically shorted across a thousand times a second to prevent burnout of the receiver front end, usually a simple diode detector.   This requires a gas filled tube called a T/R switch and a HV power supply for it, to keep it ready to instantly trigger like a strobe flash tube on a camera.  

And so on, and so on, and so on.

How would you process and interpret the noisy crap and clutter coming from the detector / receiver circuits?  Better be really good at analog / digital hardware design and construction, and high speed programming of whatever hardware ends up in the system.

And so on, and so on, and so on.

About the only radars operating in this frequency range are "small boat radars" - Google that to see what all is available and what limited utility that it has, even when designed by Raytheon, Litton, Sperry, you name it.

I've had odds and ends of 2450 MHz hardware laying around for 40 years and it never occurred to me to try to build a pulse radar with it, or even a simple receive converter.  It's not very easy at all to work on stuff in the microwave frequency ranges.

ETA

Dicking around like this is an extremely excellent way to invite The Man into your life - FCC, FAA, DHS, on down the list.  

The shitty microwave my mom had used to knock me offline 90% of the time it was used.

I was an IFF Tech (NEC 1572) and SNAP III tech (no NEC) on USS Rodney M. Davis (FFG 60).  In other words, being a frigate ET, I worked on all kinds of shit in the ET / IC / DS (FC) rates.



Now I'm a 2E171 Satellite, Wideband & Telemetry Systems Maintainer in the Air National Guard.  Come Nov. 1, I'll be a 3D171 RF & Transmission Systems Specialist.  Fucking AFSC merger clusterfuck...






 

Didn't Mythbusters shoot down that one?

I've always thought it'd be fun to throw a bag of microwave popcorn into the radome and then hot transmit.

But then again, burnt popcorn reeks something awful.

About the only thing useful for a radar set is the magnetron and associated power and control circuitry. You'll still need a receiver and proper frequency tuning circuits, control circuits, some way to convert your rf data to a format that you can display on something. Then there is the antenna array. Not to mention it would be a pretty low power set and not have very much range.





Here's a cheap bottom end radar set for about $1400 bucks. I think you'd end up spending as much money and still not be anywhere close to something like this in quality.

I doubt mythbusters could get access to a SPS-49.  I don't think there are many (if any) commercial sets that output the power a Navy air search radar does.

Yeah, I was a victim of the DS rate disesstablishment (was a 1624-DS initially), then was an FC for a couple of years (after the force conversion in 98), then crossed to ET.  1678 (GCCS-M), 9502, etc, etc...

IIRC, they did their testing onboard a USCG cutter...

I have built several high output wireless LAN/WAN setups, and i would strongly suggest you not fuck around with microwaves :) A typical microwave magnetron has ~160-180degree dispersion angle, while this may sound awesome, it is incredibly hard to build shielding that focuses that into a useful range without frying oneself.  ~2.4Ghz is not a frequency you want to be waving around, especially with the power output and dispersion available from a microwave magnetron.

If anyone actually does this please send me a PM with your address first so i can claim dibs on guns and ammo while you try to keep your liquefied organs from leaking out.