I was in one EMC test chamber on military base here in Czech. rep.. It's HUGE, they test whole trains and tanks inside... Actually it's one of the biggest in whole Europe.
Every test centre I've been too, I've always found that the EMC engineers so vague! Always nice guys, but never seem to be able to answer your question with any certainty. Maybe they're so used to getting back to you to so they can charge you for their time - or maybe its that they get fed up with all the EE's asking so many questions. :)
Frankonia make the best anechoic chamber 12:59 this is a CP, floor connection panel, they are situated close to the antenna and close to the turn table, for easy connection 13:44 All Frankonia chambers have raised floor, this one is heavy duty, all cable and optic fiber can circulate through duct under the raised floor from floor connection panel to penetration panel to control room 13:59 Those absorbers are made form mineral material laminated with thin film, those absorbers are M0 non flammable. 14:8 End cap is to hide the nylon nut at the end, this is how absorbers are fixed on shielded wall 16:17 Dyno on anechoic chambers are all shielded, this is why those dyno cost so much
I love it when there is a value on something like this. A few years back I was the lead tech & built a LIDAR bathymeter system (oceanographic survey) which was worth a cool $7m....for one instrument!....It really puts things in perspective.
Yep. Annoying. I assume cellphones aren't allowed when they are testing. They will keep boosting their own signal until every antennae in a block radius is being swamped with digital noise.
There's one like this around this size close to where I live where they stick anything in there that needs to be testing from coffee machines for aircraft to lorry's and busses. It's a BAE SYSTEMS site, where they mostly specialise on HUD's n helmets and lots of other amazing cutting edge state of the art bits, which I love! 😍 I know it's an older vid but I loves every second of it 👍🏻
Fascinating! It would have been great to show an actual testing :) Do you guys know if they use only one antenna in each room to measure the emission or do they have something like a sensor/antenna network (like a flat panel detector) so that they can have a more detailed emission-map in the end?
My work has an EMC test room... i've been in there for testing... its similar to the video but smaller. An antenna to monitor reflections, rotate it 90 degrees and test again with a spectrum analyzer. Pretty cool stuff.
The place(s) I worked that had these collected cell phones, cameras, and all recording devices at the gate. Look me up in 2050 when their nondisclosures clause expires, and I will likely have forgotten what I was even doing there. The floors were done with cones too. A bridge could be set up, and they had hanger bolts to suspend things from the ceiling, and places to put pillars up from the floor for platforms TTs etc.. Both can rotate, & or gimble.
did you check out the audio when you went thru the door ???? All the ambient just dropped huge. That's cool. BTW, love the channel man. Cheers! (From Canada)
Oersted's experiment was a current through a wire creating a Magnetic field, not an electromagnetic one. Get to grip with Maxwell's equations and the difference will become clearer.
The cone coating is carbon black and graphite mixed into paint. A German company is selling a RFI shielding paint for people wanting to shield themselves from RFI towhat end I am not sure. They sell this carbon black and graphite paint to shield electric guitar control cavities which I find to be useless. RFI does not come through or affect audio very much at all. Foil or Ferrashield will do low freq EMI which is the enemy to low noise in audio circuits. Foils costs a lot more, go figure!!
No, they aren't the same physical field. You can't move a magnet with an electromagnetic field. To shield against magnetism you need a diamagnetic material like soft iron. Mumetal is the best, but it is not good against strong fields because it tends to saturate too easily. Once that happens, it may as well not be there.
@sixstringmania a poorly conductive material. They have to be resistive so they can convert the the RF into heat. According to wikipedia a mixture of carbon and iron is very common. I think I have heard of silicone being used (I guess it would have to be silicone and some other material to be able to do the job)
It's not required because the chamber is a faraday cage. It already block all the EMF. The inside cones are there not to block the EMF but to dissipate them. Like a sound anechoic chamber. You have concrete wall to block outside sound, but have cones to eliminate inside sound.
@@alexandrevaliquette1941 I thought in the case of extreme sensitivity it could be applied to the the outside to reduce vibration which could otherwise create frequencies. Do you know if this is done anywhere?
I found it funny to hear some cellphone signals at around 34:30, the door was probably open but that little phone must be screaming its mind off to the antenna...
I've seen one like this with a suspended wire mesh floor but they can't support trucks. Oddly, when an orchestra play in an anachoic chamber there is a reverb - its sound echoing around inside the instruments, across a whole orchestra, thats a lot of space! :o)
Within the military testing chamber, do you use any form of jig to position any components that won't necessarily be connected directly to a 'chassis'?
They moved all their secret government stuff out of the city years ago. It makes me wonder who is using the old facility. The mains grounding has exothermic welded copper grids, and man made chemical electrodes everywhere under the facility. I hope you do get part of the VLA in Australia. Your political status is way more stable than Africa. I toured the first VLA in New Mexico in about 1978? I think. It is along I-10 in southern New Mexico, and now there are more in other locations.
Question: In the big room, how AWESOME would it be to bring a loud ass sound system and blast it inside and no one else would hear it. Lots of fun dance partys can be held inside :D
Well, I suppose that would be me. I design microwave radio equipment for satellites, and I make frequent use of this kind of facility. The ferrite beads they mention are the insurance against induced currents.
Yes and no. Nearby power lines would certainly create fields that would penetrate these walls, but the measuring instruments themselves are electromagnetic, not magnetic, so they wouldn't be responsive to thos efields.
That's a magnetic field. If electromagnetic fields moved magnets, compasses wouldn't work anywhere near a transmitter - which in practice would mean just about anywhere in the developed world.
It points north (or as they are in Oz, I guess they would say it points south). This chamber shields ELECTROmagnetism, not magnetism - not the same thing.
I am reminded... as i am current sitting outside a room like that... EMC testing is very boring. Dont get me wrong, im glad its boring, but at least I can watch the EEVblog while i run audio susceptibility. :)
A co-worker of mine has to sit in front of a screen during immunity test and he basically is just there to watch the numbers displayed by the device under test. So, he is (at least during the immunity tests) essantaly an expensive OCR (Optical Character Recognition) solution. Of course that is not the only thing he does, but... explain or better do not explain management why EMC testing eats so much man-hours and throughput time.
LOL! Oh man I felt the same way when I used to do Total Radiated Power and Total Isotropic Sensitivity measurements on mobile phones. Measure the phone alone, then with a dummy head and hand with fingers in different positions turning the DUT in increments of 10deg for a full 360. Ugh! Boring but necessary so hang in there! :)
I think the question was, why are they not running Linux? It's a dedicated system. Linux is a dedicated kernel. Any facility with respect for themselves that cannot afford to build their own OS from the bottom uses Linux, so it's a mystery indeed.
It sounds like the guy you were interviewing didn't really want to be there... Interesting info in this video (I have never seen this kind of equipment before... And that anechoic room.......) but the video was overall a bit boring.
I was in one EMC test chamber on military base here in Czech. rep.. It's HUGE, they test whole trains and tanks inside... Actually it's one of the biggest in whole Europe.
Every test centre I've been too, I've always found that the EMC engineers so vague! Always nice guys, but never seem to be able to answer your question with any certainty. Maybe they're so used to getting back to you to so they can charge you for their time - or maybe its that they get fed up with all the EE's asking so many questions. :)
Frankonia make the best anechoic chamber
12:59 this is a CP, floor connection panel, they are situated close to the antenna and close to the turn table, for easy connection
13:44 All Frankonia chambers have raised floor, this one is heavy duty, all cable and optic fiber can circulate through duct under the raised floor from floor connection panel to penetration panel to control room
13:59 Those absorbers are made form mineral material laminated with thin film, those absorbers are M0 non flammable.
14:8 End cap is to hide the nylon nut at the end, this is how absorbers are fixed on shielded wall
16:17 Dyno on anechoic chambers are all shielded, this is why those dyno cost so much
I love it when there is a value on something like this. A few years back I was the lead tech & built a LIDAR bathymeter system (oceanographic survey) which was worth a cool $7m....for one instrument!....It really puts things in perspective.
It's the finishes on/in the wood tables that cause problems at high frequency, btw. At least according to the IEC 61000-4-3 standard text
34:38, somebody's phone is desperately trying to get a signal. :-)
Yep. Annoying. I assume cellphones aren't allowed when they are testing. They will keep boosting their own signal until every antennae in a block radius is being swamped with digital noise.
what's fun is closing the door behind you, and standing in the center. It is.. SOOOOOO unbelievably quiet. Maddeningly quiet.
Different kind of anechoic chamber.
@@24pavlo wrong. I worked in EMC for 7 years, access to chambers daily
There's one like this around this size close to where I live where they stick anything in there that needs to be testing from coffee machines for aircraft to lorry's and busses.
It's a BAE SYSTEMS site, where they mostly specialise on HUD's n helmets and lots of other amazing cutting edge state of the art bits, which I love! 😍
I know it's an older vid but I loves every second of it 👍🏻
@JumperOneTV Yeah, indoor climbing wall and trapeze set in the lab would be cool!
I am surprised not to see a handler inside the GTEM. Nice to have.
Never seen something awesome like that!!!
me too!
Got it. Yep. Right. Yep. Right. Yep. Got it.
I just kept thinking of the walls closing in :P
Fascinating! It would have been great to show an actual testing :) Do you guys know if they use only one antenna in each room to measure the emission or do they have something like a sensor/antenna network (like a flat panel detector) so that they can have a more detailed emission-map in the end?
worked around these when i was in the aircraft TCAS and GPS systems business. nice chamber.
My work has an EMC test room... i've been in there for testing... its similar to the video but smaller. An antenna to monitor reflections, rotate it 90 degrees and test again with a spectrum analyzer. Pretty cool stuff.
The place(s) I worked that had these collected cell phones, cameras, and all recording devices at the gate. Look me up in 2050 when their nondisclosures clause expires, and I will likely have forgotten what I was even doing there. The floors were done with cones too. A bridge could be set up, and they had hanger bolts to suspend things from the ceiling, and places to put pillars up from the floor for platforms TTs etc.. Both can rotate, & or gimble.
did you check out the audio when you went thru the door ???? All the ambient just dropped huge. That's cool. BTW, love the channel man.
Cheers!
(From Canada)
The host "LET'S SEE HOW MUCH I CAN EXAGGERATE AND STRETCH MY FACE AND EYES"
Nice! I miss working with RF. 8 to 40ghz good thanks
Interesting how the sound changes too as you enter the chamber.
Oersted's experiment was a current through a wire creating a Magnetic field, not an electromagnetic one. Get to grip with Maxwell's equations and the difference will become clearer.
I went in the Semi Anechoic chamber at Jaguar Landrover only a few weeks ago xD
Dave, you would make a great a TV Show host !!
Sweet tour guys - thank you. :)
The cone coating is carbon black and graphite mixed into paint. A German company is selling a RFI shielding paint for people wanting to shield themselves from RFI towhat end I am not sure. They sell this carbon black and graphite paint to shield electric guitar control cavities which I find to be useless. RFI does not come through or affect audio very much at all. Foil or Ferrashield will do low freq EMI which is the enemy to low noise in audio circuits. Foils costs a lot more, go figure!!
You two are a mirror image when it comes to energy level :P
give him a redbull or a cup of coffee ;D
What kind of testing are they doing in such a chamber exactly? Why do they put vehicles in it?
No, they aren't the same physical field. You can't move a magnet with an electromagnetic field. To shield against magnetism you need a diamagnetic material like soft iron. Mumetal is the best, but it is not good against strong fields because it tends to saturate too easily. Once that happens, it may as well not be there.
really cool video, thanks to the both of ya :)
Joking around about which frequencies are DC... Har har! EE humor!
that's....that's..... the paradise !!!
( yes I live in a very noisy neighborhood )
The room cleans itself
1.8M in that facility, cant buy him a mic so we can hear him.
@sixstringmania a poorly conductive material. They have to be resistive so they can convert the the RF into heat.
According to wikipedia a mixture of carbon and iron is very common. I think I have heard of silicone being used (I guess it would have to be silicone and some other material to be able to do the job)
Rule No.1 of interviewing: Shut up and let people talk.
When are you going to tear-down the Keithley instruments (fA and nV), Dave?
Hi, why is the same treatment not applied to the outside (facing outwards) of anechoic chamber?
It's not required because the chamber is a faraday cage. It already block all the EMF.
The inside cones are there not to block the EMF but to dissipate them.
Like a sound anechoic chamber. You have concrete wall to block outside sound, but have cones to eliminate inside sound.
@@alexandrevaliquette1941 I thought in the case of extreme sensitivity it could be applied to the the outside to reduce vibration which could otherwise create frequencies. Do you know if this is done anywhere?
I found it funny to hear some cellphone signals at around 34:30, the door was probably open but that little phone must be screaming its mind off to the antenna...
I've seen one like this with a suspended wire mesh floor but they can't support trucks. Oddly, when an orchestra play in an anachoic chamber there is a reverb - its sound echoing around inside the instruments, across a whole orchestra, thats a lot of space! :o)
I want my garage fitted with those cones, and my bedroom as well. Hell, make it the bathroom too.
Hmm, a big flat solid floor. That's going to reflect audio, isn't it? Is that room used the way it's presented in the video? I hear echoes!
@rapsod1911 When time permits, things are hectic at the moment unfortunately.
Within the military testing chamber, do you use any form of jig to position any components that won't necessarily be connected directly to a 'chassis'?
They moved all their secret government stuff out of the city years ago. It makes me wonder who is using the old facility. The mains grounding has exothermic welded copper grids, and man made chemical electrodes everywhere under the facility. I hope you do get part of the VLA in Australia. Your political status is way more stable than Africa. I toured the first VLA in New Mexico in about 1978? I think. It is along I-10 in southern New Mexico, and now there are more in other locations.
Brilliant excellent wow brilliant excellent
it's not the biggest on the south hemisphere.
24 x 11 x 10 (m) is the size of one here in Brazil
www.lit.inpe.br/emc
Question: In the big room, how AWESOME would it be to bring a loud ass sound system and blast it inside and no one else would hear it. Lots of fun dance partys can be held inside :D
@thewii552 Someone had their phone with them obviously.
Well, I suppose that would be me. I design microwave radio equipment for satellites, and I make frequent use of this kind of facility. The ferrite beads they mention are the insurance against induced currents.
If you are stuck there, you will NOT be able to make an emergency phone call LOL
Now that is a big door!
I put term ,,Anechoic" into the english to slovak dictionary, and it translated it as : ,,The lover of anectodes" (in back translation to english)
Yes and no. Nearby power lines would certainly create fields that would penetrate these walls, but the measuring instruments themselves are electromagnetic, not magnetic, so they wouldn't be responsive to thos efields.
ConePorn. But to me, almost every EMC testing technician is a ConeMan. And EMC is considered magic and sorcery.
as they walked inside i noticed the room is audio anechoic as well
Drool at the R&S 40 GHz SA!
I've been in one of those, I almost went crazy, because i rely much on my hearing
Now that is a big door.
i imagine it is quite good for noise cancellation?
Is that a state of the art cassette radio there..
We have one of these at work. It sounds really odd when you walk in especially when you are talking to someone.
That's a magnetic field. If electromagnetic fields moved magnets, compasses wouldn't work anywhere near a transmitter - which in practice would mean just about anywhere in the developed world.
It points north (or as they are in Oz, I guess they would say it points south). This chamber shields ELECTROmagnetism, not magnetism - not the same thing.
Very interesting !! Thanks.
@depomb I want room of that size for my lab. And for my gym too..
@EEVblog I wander if they got a signal. ;)
The phone keeps on searching for a cell. You can hear this in the video. So the chambers are working :-).
@DanFrederiksen In Australia all cars must be EMC tested.
Awesome!
Dave, your camera makes a lot of clicking noise when handled, something to keep in mind when filming standing up
This room isn't for audio. It is for radio. The acoustic properties are not important.
When that door opened, I expected to see lots and lots of eggs.
I am reminded... as i am current sitting outside a room like that... EMC testing is very boring. Dont get me wrong, im glad its boring, but at least I can watch the EEVblog while i run audio susceptibility. :)
A co-worker of mine has to sit in front of a screen during immunity test and he basically is just there to watch the numbers displayed by the device under test.
So, he is (at least during the immunity tests) essantaly an expensive OCR (Optical Character Recognition) solution. Of course that is not the only thing he does, but... explain or better do not explain management why EMC testing eats so much man-hours and throughput time.
LOL! Oh man I felt the same way when I used to do Total Radiated Power and Total Isotropic Sensitivity measurements on mobile phones. Measure the phone alone, then with a dummy head and hand with fingers in different positions turning the DUT in increments of 10deg for a full 360. Ugh! Boring but necessary so hang in there! :)
At least a $1,000,000 of that budget went into that ridiculous door.
Windows XP!? CRTs?!
I think the question was, why are they not running Linux? It's a dedicated system. Linux is a dedicated kernel. Any facility with respect for themselves that cannot afford to build their own OS from the bottom uses Linux, so it's a mystery indeed.
man, sound inside is far better LOL
My question: Does an anechoic chamber get tested in an anechoic chamber ;)?
Wonder what would it be like to play guitar inside that room.
Those doors just kept getting bigger
It sounds like the guy you were interviewing didn't really want to be there... Interesting info in this video (I have never seen this kind of equipment before... And that anechoic room.......) but the video was overall a bit boring.
Brilliant
china huawei shenzhen has a much bigger one which can put can put a truck with a base station tower on it.
what are those cones made of?
Who cleans that room?
20:58 GSM interference...in a shielded room...
@rapsod1911 Damn, good point...
how annoying is this interviewer but he does dig pretty deep which is good :)
what is the floor made of?
Don't turn it on, take it apart!
That second room looked like CGI haha!
That's one hell of an Iron Maiden
Yep
Ahhh, nice music, cool.
And remember, wear protection!
So... I couldn't help but notice the floors are flat. :)
OMG.. Can the guy who works there make it any duller?
+Joanna Hammond He's an engineer, not a talk-show presenter.
True.
So in other words, no.
+Joanna Hammond Not so boring if you have the critical mass of rf knowledge required to digest the content.
+Ed Price Yep!
...even table height and distance from table to wall... for conducted emissions testing. As if it matters.
That makes sense :)
Oh Dave I would take Mitsubishi over Ferrari anyday...
Probably cost 30x the price if they used ferrite tiling.