Russian DYI death rays - Page 1
Forum section: electronics / projects

author: zapta
author_rank: Super Contributor
timestamp: September 11, 2014, 07:52:10 am
content: It's in Russian but understandable nevertheless. Don't try it at home.?????.??

author: wraper
author_rank: Unknown
timestamp: September 11, 2014, 08:19:43 am
content: That is Luhansk, Ukraine. You can even hear shelling. Yes they are filming when war is going on.

author: DutchGert
author_rank: Frequent Contributor
timestamp: September 11, 2014, 09:10:21 am
content: Wtf....Guess what happens when pointing it at a person... Weirdo's

author: janekm
author_rank: Unknown
timestamp: September 11, 2014, 09:16:35 am
content: Some of their videos are really cool, actually (and disturbing).The video showing radio propagation patterns in real-world environments with the magnetron and the "walkman" is pretty much the best thing I've seen for getting a feel for how weirdly radio behaves in the built environment.

author: Rerouter
author_rank: Super Contributor
timestamp: September 11, 2014, 09:25:56 am
content: This to me kind of raises the question to what would be the minimum safe distance for a magnetron powered on and running, considering all that needs to happen to a microwave is the glass to be smashed, how far would you aim to run?

author: eneuro
author_rank: Super Contributor
timestamp: September 11, 2014, 10:06:05 am
content: Quote from: Rerouter on September 11, 2014, 09:25:56 amMany more stupid close experiments without any shielding, like those where he holds light bulbs in his hand in a place where in video above lights were bright ON?????!BTW: Which is the sense of putting magnetron in closed cylinder (pipe) side not its bottom?Some kind of resonance and/or standing waves is needed in microwave oven to cook something, so it requires multiplies of microwave wave length box dimensions?Why not to put simply magnetron output into long metal pipe closed in one end with the hole?Of course reflections from flat metal parts pointed to still might be dangerous, but it looks like far more save for person holding it than showed in those stupid videos...and radar is the first thing I'm thinking about, but I haven't got any datasheets how powerfull those police radars are, but some antyradars detectors are capable detect those units far away where they are used so it must be significant power source of microwaves too, I guess... but they (police) fire microwaves into cars full of persons from different distances is it safe to which distance

author: wraper
author_rank: Unknown
timestamp: September 11, 2014, 10:13:48 am
content: http://www.turnpoint.net/wireless/cantennahowto.htmlMicrowave oven have the same frequency as wifi BTW.

author: mcinque
author_rank: Unknown
timestamp: September 11, 2014, 11:19:59 am
content: Even if it's extremely stupid do this kind of things, AFAIK microwaves are defintely not ionizing radiatons so the danger is quite limited (skin burns for example), dont you?

author: mzzj
author_rank: Super Contributor
timestamp: September 11, 2014, 11:35:19 am
content: Quote from: Rerouter on September 11, 2014, 09:25:56 amno need to run, just step back 3 feets and you are fine.

author: Dago
author_rank: Frequent Contributor
timestamp: September 11, 2014, 11:51:19 am
content: Quote from: mcinque on September 11, 2014, 11:19:59 amAFAIK the biggest danger is for your eyes. Because the surface of the eye has no feeling (or not much) but plenty of water (that heats up) it is pretty easy to heat it up to the point where the proteins coagulate and you permanently damage your eye.

author: DanielS
author_rank: Frequent Contributor
timestamp: September 11, 2014, 11:55:44 am
content: Quote from: Rerouter on September 11, 2014, 09:25:56 amNo need to run if the RF screen (perforated metal layer between the inner and outer glass) is not broken and if you are close enough to worry about microwave exposure, it would probably be simpler and safer to hit the STOP button or pull the plug than run.

author: VK5RC
author_rank: Unknown
timestamp: September 11, 2014, 12:21:49 pm
content: Those guys are crazy, RF burns to skin are quite nasty (and deep) take quite a while to heal. I am aware of increased cataracts in microwave RF techs.The 'safe' distance from a 600W 2.3GHz from a (approx 8dB gain) 'cantenna using VK3UM's EMR calculatorhttp://www.vk3um.com/emr%20calculator.htmlUsing Australia's ACMA 10W/m^2 'safe limit'ON AXIS exclusion zone = 4.4moff Axis 0.6m

author: ConKbot
author_rank: Super Contributor
timestamp: September 12, 2014, 01:06:05 am
content: Quote from: mcinque on September 11, 2014, 11:19:59 amIndeed, no broken DNA, just blindness, deep tissue burns, possibly internal organ damage depending on the frequency. (I think 2.4Ghz would be a bit short to get to internal organs but I havent read anything on the topic)Expanding on what VK5RC mentioned (antenna gain), the easiest way to get dangerous levels of RF power is high gain antennas. In the beam of a 10 dBi antenna fed from a 600W source, the beam intensity is the same as being the same distance from a 6kW transmitter with an omnidirectional antenna (AKA 6kW EIRP ).Even a 1W transmitter can start getting beyond safe personnel limits in certain bands.But not to be all super serious about elf and safety, I saw an older article from microwavejournal recently, about a microwave oven weed burner. I cant get the article (behind a paywall, for a 9 year old article :p ) but the images turn up in google image search, so F'eminitial testingdrawing of the microwave arrayserious businessIIRC they fed it from a 3 phase PTO generator on a tractor when they tested a 'fieldable' unit.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 12, 2014, 03:17:42 am
content: No matter what your antenna gain is,if your Transmitter is a 1watt unit,that is all the power you have to play with.If it really did what some people think,it would be an "over-unity" device.

author: calexanian
author_rank: Super Contributor
timestamp: September 12, 2014, 04:27:56 am
content: You see.. Here in 'murica we blow stuff up the old fashioned way.... with black powder... Was that an actual incoming shell in the second video you can hear in the background or a sound effect? Valid question in that part of the world right now!

author: zapta
author_rank: Super Contributor
timestamp: September 12, 2014, 07:45:01 am
content: Quote from: calexanian on September 12, 2014, 04:27:56 amIt was the crazy Russian gun guy shooting a YouTube video nearby (it's an extremely popular YouTube channel):

author: eneuro
author_rank: Super Contributor
timestamp: September 12, 2014, 09:31:50 am
content: Quote from: wraper on September 11, 2014, 10:13:48 amIt is interesting and now clear why they put magnetron in cans of such dimmensions in this position- to make primitive waveguides for those a few GHz RFFound thiswiki: Waveguide (electromagnetism) - analysis, so it might be interesting to make DIY wifi directional antena.At 2.4 GHz RF wave length is 125mm, so quater wavelength with corrections for antenas around 30mm (3cm)

author: TerraHertz
author_rank: Super Contributor
timestamp: September 12, 2014, 09:43:57 am
content: Let's hope no military guys in the vicinity decide to fire a HARM missile, to take out that 'strange enemy radar system'.In Bosnia the defense forces were doing that, to make NATO warplanes waste HARM missiles. Just set up any old microwave oven on a hillside with the door open and the safety interlocks defeated. Ovens use half-wave rectified AC, so the magnetron runs in pulse mode. Would make a really crappy radar transmitter, but the missiles don't care and home in on it anyway.

author: mcinque
author_rank: Unknown
timestamp: September 12, 2014, 11:51:24 am
content: Quote from: Dago on September 11, 2014, 11:51:19 amQuote from: ConKbot on September 12, 2014, 01:06:05 amOh.I didn't knew/consider that. It's an extremely important safety issue.

author: rolycat
author_rank: Super Contributor
timestamp: September 12, 2014, 12:21:04 pm
content: Quote from: zapta on September 12, 2014, 07:45:01 amI don't think Russians are too welcome in Ukraine right now, particularly heavily armed Russians.And that quadrotor video is a fake - there's no way it could lift that sort of payload.

author: ConKbot
author_rank: Super Contributor
timestamp: September 12, 2014, 01:41:01 pm
content: Quote from: rolycat on September 12, 2014, 12:21:04 pmhttp://www.hobbyking.com/hobbyking/store/beerlift.aspCheck out the weights on the 700 class (under 700 mm from motor to motor on the multicopters) winner was almost 20Kg. #7 was over 8 lbs with a quadcopter of about the same size as the pictured one. I wouldnt rule it out that easy

author: eurofox
author_rank: Unknown
timestamp: September 12, 2014, 01:57:18 pm
content: Quote from: wraper on September 11, 2014, 08:19:43 amNo .... no, it is the Russian army in Jurmala

author: German_EE
author_rank: Super Contributor
timestamp: September 12, 2014, 05:14:06 pm
content: A tale for you. I was once an expert witness speaking on behalf of a manufacturer of commercial microwave ovens. The owner of one of these ovens (a Chinese takeaway) had got fed up of opening the door, putting the food in, closing the door and then hitting the start button each time so he removed the door and replaced it with a metal plate with a 5cm x 30cm hole in it. He also defeated two safety interlocks.The oven was then left running and if they wanted to heat a meal they just put it through the slot, waited, then took the plate out again when the food was hot. They only sensed that there was trouble when their fingernails started dropping off and they had trouble moving their fingers. Three people lost all the fingers on one hand and one person lost the sight of an eye (for her the slit was at eye level).Naturally they took the manufacturer to court because nowhere in the instructions did it say 'do not remove the door and replace it with a metal plate'. They lost, the judge actually called them idiots.

author: mcinque
author_rank: Unknown
timestamp: September 12, 2014, 06:38:35 pm
content: Quote from: German_EE on September 12, 2014, 05:14:06 pmBecause they are!

author: wraper
author_rank: Unknown
timestamp: September 12, 2014, 08:03:30 pm
content: Quote from: zapta on September 12, 2014, 07:45:01 amBut he is not Russian, his name is Kyle Myers.

author: wraper
author_rank: Unknown
timestamp: September 12, 2014, 08:20:53 pm
content: Quote from: eurofox on September 12, 2014, 01:57:18 pmWell, you know, if watch our bullshit news every day (broadcast directly from Washington) it wouldn't be hard to believe. I know some people in Mariupol and Izmail (Ukraine), though. And they are no excited (to put it mildly) by the new government at all. I was in Ukraine myself repairing stuff when people were burned alive in Odessa (200km from where I was) by local Nazis, that day I decided to return back next day FFS.

author: eurofox
author_rank: Unknown
timestamp: September 12, 2014, 08:34:08 pm
content: Of course the true is RT, that is the only true, no russians in Crimea to annex it

author: wraper
author_rank: Unknown
timestamp: September 12, 2014, 08:38:04 pm
content: Propaganda everywhere, there are no good guys. Thou most Crimean were not against it, just because they are mostly Russians. People in Ukraine west and south/east are very different, both by language and political view.

author: zapta
author_rank: Super Contributor
timestamp: September 12, 2014, 09:32:12 pm
content: Quote from: wraper on September 12, 2014, 08:03:30 pmHere is the proof he is Russian:

author: eneuro
author_rank: Super Contributor
timestamp: September 12, 2014, 09:37:48 pm
content: Quote from: TerraHertz on September 12, 2014, 09:43:57 amI've made microwave oven teardown some time ago and just want to understand how those parts are connected and how magnetron is powered, while there is no specs on it about its operating voltage and power ratingsBut magnetron radiating RF element is close to 30mm (3cm long)I found therehttp://en.wikipedia.org/wiki/Dielectric_heatingthatQuoteand herehttp://en.wikipedia.org/wiki/Cavity_magnetronits principles, but there were no typical magnetrons specs.This has two connectors only and it looks like diode connected to ground from one of this high voltage capacitor rectifiers AC voltage?However, those a few turns coil in the middle of this transformer is a mistery for the moment too, while expected high voltage windings to be connected to magnetron somehow.I was even more supprised that thisHVR-1X3 High Voltage Power Diodes Standard and Ultra Fast Recoverydiode rated to 12kV 0.5A and surge current 8ms up to 30A is connected to... ground and as i remember one of HV tarsformer windings was connected to transformer case?How those microvawe ovens are safe-it is better not to open those things while when you see so many "DANGER HIGH VOLTAGE" tags inside starting think to do not connect it to 230VAC mains no moreBTW: It is quite good for Dave videoblog maybe, while its circuit looks simple, but... I'd like to have its schematics and ensure it is save to touch its case

author: zapta
author_rank: Super Contributor
timestamp: September 12, 2014, 09:42:12 pm
content: This could be a great idea for eevblog teardown episode.

author: eurofox
author_rank: Unknown
timestamp: September 12, 2014, 10:55:46 pm
content: Quote from: wraper on September 12, 2014, 08:38:04 pmI know them much better than you, my wife who past away was from Lugansk, I'm married again with someone from the south of Ukraine both native Russian speaker, don' try to teach how they are and how they think.I was in Russia from north to south and from east to west, know a lot of people from professional and private experience.I know very well the history including your country that I know very well including the relation with the native Latvian and the Russian minority.I don't say that USA is always right with international politics just like Russia but there is one big difference, one is a democracy and the other a dictature with the dictator telling what 145 million people will do and they are all scare to disagree with him.I'm a real European in soul and I'm happy that the EU and NATO exist because we never got such a long time peace in Europe.This board is not the right place for this kind of discussion but Ukraine should have the right to decide what they want, stop corruption and start democracy without any action from Russia.We are not in the middle ages anymore.eurofox

author: LukeW
author_rank: Frequent Contributor
timestamp: September 13, 2014, 03:53:13 am
content: Quote from: eneuro on September 12, 2014, 09:37:48 pmThere is a good description of how the magnetron is powered in a typical microwave oven, typical voltages and what the voltage doubler does.http://www.microtechfactoryservice.com/doubler.htmlIf you ignore the magnetic field and the physics of how the magnetron is generating RF from the electron cloud, you can basically just think of it as a thermionic vacuum-tube diode.Also note the filament heater winding coming off the transformer.A typical microwave oven transformer will have the terminals for the primary winding, a distinct HV heavily insulated winding coming from one side of the secondary, probably no wire for the other side of the secondary (tied to ground via the transformer case/core), plus another pair of wires which won't have HV insulation - these are the filament wires to the magnetron.

author: SeanB
author_rank: Super Contributor
timestamp: September 13, 2014, 04:55:59 am
content: Also every microwave oven I ever took apart has a schematic of the wiring inside the case somewhere, most commonly inside the outer case on the side where the electrics sit.The parts shown are the capacitor, the high voltage diode, and the transformer has the heater winding as the few turns of well insulated wire, as it runs at 2kV from the voltage doubler.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 13, 2014, 06:42:13 am
content: Quote from: rolycat on September 12, 2014, 12:21:04 pmReally depends which part of Ukraine you mean. Most of Eastern Ukraine seems quite disappointed theydidn'tget Russian heavy armored support.QuoteHere's a lady who would disagree with you:

author: nctnico
author_rank: Super Contributor
timestamp: September 13, 2014, 08:33:59 am
content: Quote from: mcinque on September 12, 2014, 06:38:35 pmI would call it lack of education. If you ever are having breakfast in a hotel you can observe how many people have no clue on how to operate the bread toaster.

author: Artlav
author_rank: Frequent Contributor
timestamp: September 13, 2014, 09:33:12 am
content: Quote from: German_EE on September 12, 2014, 05:14:06 pm

author: eneuro
author_rank: Super Contributor
timestamp: September 13, 2014, 06:26:37 pm
content: Quote from: LukeW on September 13, 2014, 03:53:13 amAccording to schematics from link you providedthere is also 5kV 700mA fuse between transformer high voltage windings and HV capacitor, so when capacitor or diode shorts circuit to ground it breaks I guessIt looks like there is nice HV charge pump with DC powering magnetron, but its inputs polarity does matter?There are no +/- marks on its inputs and is also powered by AC those few turns from transformer in the middle, so while it heats up some kind of resistance inside magentron input, HV is between this heated element and ground, so of course those a few turns have to be well isolated, but it does not matter how this HV connector is attached to magnetron?One of last unknowns I think is what happends if on transformer primary we provide shifted in phase 230VAC voltage eg. using triac, so there can be voltage smaller in peak value than 325V in the case of 230VAC input, lets say at the end of 50Hz half wave 2.5ms before next zero crossing so 135 degs in phase 0.7Vmax, around 230V, so if we provide such pulses we get in this charge pump voltage doubler 4kV 70% of its available maximum voltage to magnetron if it were no phase shifts and only turning on/off transformer input-does magetron can run on lower DC voltage than those 5.6kV applied to its voltage cathode and still output 2.45GHz RF?I mean pulses also 50Hz or 60Hz, but shorter shifted in phase between 90-180 degrees, so at lower voltage maximum than normal 230VAC so between 0V-325Vmax transformer primary input.Which is minimum operating voltage of magnetron, also there might be temperature limit so some time needed to heat up ?So, general question is how do they make variable microwave oven output power-by changing its pulses length or simpy turn on/off for a given amount of 20ms periods (group driving), while I do not expect H bridge driving of rectified 230VAC mains there- I saw a few relays on electronics board I guess, but do not examined it so far...More detailed magnetron specs needed I think to predict what happends when we provide lower than nominal volateges

author: Zero999
author_rank: Super Contributor
timestamp: September 14, 2014, 07:31:07 pm
content: Quote from: eneuro on September 13, 2014, 06:26:37 pm1) Polarity is important. To understand this properly, look up how the cavity magnetron works.2) Of course, the filament is just a heater and is resistive so AC is fine.QuoteI believe the magnetron has a negative resistance, like a neon lamp, so the current needs to be limited. In this case the reactance of the capacitor ion the voltage double will limit the current quite nicely.Reducing the supply voltage will probably reduce the current to a point when the magnetron fails to oscillate and the frequency could also be affected. As the filament is also powered from the same transformer, I'd suspect this would happen sooner because it would become too cool to emit electrons properly.The power output is reduced by pulse width modulating the input to the transformer at a very low frequency. Some newer microwaves replace the large transformer with an inverter and rectifier, thus forming a switched mode power supply and the power can be more efficiently regulated by either reducing the current or higher frequency PWM.

author: nctnico
author_rank: Super Contributor
timestamp: September 14, 2014, 07:50:57 pm
content: I'm wondering: would it be possible to hack a magnetron from a microwave into a transmitter for Wifi? I guess not but maybe someone went ahead and tried it anyway. Or would a pulsed radar be the best use besides wrecking stuff and cooking food?

author: SeanB
author_rank: Super Contributor
timestamp: September 14, 2014, 07:58:58 pm
content: Modulating it at WiFi data rates would be difficult, way too much capacitance in the inside of the shielded case from the RF filtering for a start, and most microwave oven magnetrons are pretty poor at starting up, they tend to draw low current until the critical level is reached and the cavities start to resonate, then it takes a few cycles more for them to build up to full power. You will not notice a few extra microseconds of start time, but your wifi will. With 50/60Hz modulation it is not going to make a difference over a cycle.Using a TR switch that will handle the full power output to reduce this will also have issues. there is a reason RADAR transmitters monitor the pulse output and use that to start a range scan, it does vary slightly and gives jitter.

author: eneuro
author_rank: Super Contributor
timestamp: September 14, 2014, 08:52:10 pm
content: Quote from: Hero999 on September 14, 2014, 07:31:07 pmI do not mean reversing grounding with this HV positive magnetron DC voltage connectorWhile filnament heating is about 3VAC it does not change too much 4.6KVDC on one of those connector pins, so I guess it does not matter how those 2 magnetron positive pins are plugged-simply do not remember in which position it was connected, and while do not planned use this microwave oven again, disconnected it and forgot for a few months, happy with quite solid transformer which can be reusedif one of SECONDARY HV wire disconnected from its case-else one can have 2.3kV on transformer caseI've disconnected it from transformer case and soldered another connector, so now I've 2.3kV transformer secondary isolated from its core, so one have to be carefull if wants to reuse this transformer if not removeing completly its HV secondaryThis is one of found schematics of microwave oven circuit from web- two pins positive HV voltage connector marked on the bottom with circle red.There is no +/- marks on this magnetron connector-DC ground is on magnetron case and is connected with grounded HV transformer secondary and a few wires in the middle for filnament heating in oryginal design.Quote from: Hero999 on September 14, 2014, 07:31:07 pmMaybe replacement of the transformer not needed in DIY microwave oven, but by adding H bridge after rectified AC mains change those pulses of corse remember about possible transformer primary designed for 50Hz/60Hz so maybe core saturation issues when trying to drive it in strange ways without AC full cyclesJust finishing other pulse spot welder project where also transformer is used and similar challenges, so it looks like oryginal microwave oven control electronics can be replaced by similar circuit to be able maybe better drive magnetron, but with completly closed waveguides (no windows like in oryginal microwave).Idea is to put something to heat-for example etched PCB in temperature resistive glass and fine tune magnetron to deliver amount of power needed to heat up etched PCB copper to required temperatures 40*C-50*C.It could be used to heat other things too if we could quite acurate control magnetron output power in clossed (no RF emissions ) waveguided microwave oven. Additionaly thermaly insulated environment, so calculate amount of power deliver and feed back gained temperature for fine control.

author: amyk
author_rank: Super Contributor
timestamp: November 21, 2014, 02:46:03 pm
content: The same guy now playing with another type of "death ray"? ?!??.?????