after 10 days of construction our brand new EMC chamber is done I can't wait to
show this to you guys watch this here's all the wireless networks that are
around here they just closed the door behind us but it takes about uh 5
seconds for your phone to go oh oh no actually I can't see any of those
anymore and then maybe a couple more seconds and it's going to go huh I got
absolutely nothing zip zilch NADA this
is going to open up a whole new world of testing that would have been completely
impossible for us before like how good is the reception on the latest iPhone is
your new TV making your controllers disconnect is your ISP provided Wi-Fi
router really so bad you have to replace it with one of these but wait a second
you might think why would you spend weeks and thousands of dollars building
this when you could just follow this simple guide from Frank Tano on building
a Wi-Fi blocking sleep thing and just do
all your testing in there and the thing is you're not entirely wrong I mean in
science class we all learned that to block electromagnetic waves it's as
simple as wrapping an object or space and conductive material grounding it and
you got a faraday cage it's essentially what this is but watch this if I stick
this tiny wire through this hole I'm going to go from
-30 DB to more like - 70 how is that
even possible the door still closed I'm still inside a faraday cage
well here's the thing while every
electromagnetically shielded enclosure is a faraday cage not every Faraday cage
is a shielded enclosure and depending on
the purpose of the cage there are numerous design considerations that must
be accounted for let's say the purpose of our cage was to protect an occupant
from a lightning strike well a grounded Box made of chain link fence would do
the job nicely but the radio waves that we rely on for cellular signals Wi-Fi
and Bluetooth they would have no trouble at all passing through that and the
higher the frequency or the shorter the wavelength of these signals the more
challenging they are to block and we saw this in action back when we bought those
silly radiation blocking Wi-Fi router enclosures on Amazon even though they
used a relatively fine mesh and they did reduce our signal strength they still
allowed our Wi-Fi to function meaning that a ton of EMF was still getting
through in that case that was a good thing because a WI router with no signal
at all wouldn't be very useful but for an EMC chamber any leakage from the
noisy environment around it is going to completely invalidate our test results
thankfully our unit isn't cobbled together out of office paper holders but
rather was installed personally by the owner of Raymond EMC whose encyclopedic
knowledge of these things has been incredible helping us learn why sorry
prepper YouTube building a proper shielded test chamber is a lot more
complicated than this or this or this or
this segue to our sponsor Raymond EMC I
actually didn't know at the time that I was filming it that they sponsored this
video by giving us the whole RF chamber
and they didn't mention that when I was talking to them whatever it doesn't matter the point is they did so make
extra sure to go and check them out after this video if you need a shielded
enclosure and a coic chamber or a shielded tent the point of my wire in
the hole demo was to show you guys that
when you want to eliminate background electromagnetic interference the devil's
in the details I mean sure any piece of
metal that stands in its way can be a barrier for an electromagnetic wave
that's why we always recommend placing your wireless router away from metal
objects because the wave strikes them a current is induced and the wave ends up
more canceled than Kanye West the tricky part is that if you want to get all of
them the electrical charge of the entire enclosure needs to be homogeneous AKA
there can be no holes or cracks that means that this tinfoil hat then is only
marginally more useful for blocking electromagnetic waves than this regular
one from LTT Store.com and only one of
its problems is that it's not grounded so then shielded enclosure Step One is
connecting it to ground but even that is easier said than done for starters I was
2 weeks ago old when I found out that our floor in here simply isn't flat
enough sure fing so we needed to pour a
thin concrete slab on top of that is a 6
mm poly Vapor Barrier and then we get into the real Biz starting with a 1/8 in
Masonite board that acts as an electrical insulator between the
enclosure itself and the floor then from the enclosure we connect the single
point ground stud directly to the ground of our electrical panel which wait a
minute why do we care about insulating the chamber if we're just going to
ground it anyway ah if we let the en
closure touch the concrete directly we could end up with multiple paths to
ground that could cause Eddy currents and turn the entire enclosure into an
antenna which obviously not ideal from
there the enclosure is basically a box made of wood panels with steel sheet on
either side but joining them together is
more complicated than it looks every single one of these screws needs to be
torqued exactly to spec and if it isn't
the minute gaps between threads can be a path for electromagnetic waves to get
through and this is not just theoretical
paranoia on ours there was a single screw that wasn't tightened exactly the
same as the others and the enclosure failed the 18 GHz test fortunately these
guys are pros and they were able to quickly track down the Rogue screw and
tighten it so with all the panels tightened together we now have a
properly constructed steel box but this is where things get really complicated
how do you put a door in something like this I am so glad you asked back to our
point from earlier if all we were trying to do is make a faraday cage we could
just run a single wire from this door to the enclosure and we're good but if we
want the whole thing to be homogeneously bonded we need to get a little fancier
what you're looking at right here is a brass knife edge that goes into a
brilliant copper contact frame this ensures that the entire door panel acts
like any other panel of the Box rather than allowing excess charge to build up
on one side of it compared to the other and check this out outside handle made
of metal nice and strong inside handle
made of fiberglass because if it was metal it could potentially become a
reflector and screw with our test results at least in theory how exactly
do we know that it works well first we need to make sure we're properly
hydrated by taking a drink from this fantastic insulated water bottle LTT
store.com then we need to mosey over to this fancy Spectrum analyzer and Signal
generator that costs I'm sorry
$100,000 don't drop it what's really wild is that the guys from Raymond EMC
were actually saying that these kinds of tools have become much less expensive in
recent years yikes I'm really glad I
don't need to buy one of these I can just use theirs while they're here so what we're looking at right now is the
signal generator is creating a 1 GHz signal I'm pointing this antenna at it
and it clearly shows up on our Spectrum analyzer now if Alex closes the door
you'll be able to see that boom that Peak completely goes away that means the
system works now we were asking the Raymond DMC guys if they had any crazier
demos than this and they were like well
here's the thing imagine that the chamber is like brakes on a car this
right here that's your speeding car and now the car is stopped like really
really really well oh okay fair enough
good demo then so now we've got a sealed steel enclosure that blocks
electromagnetic waves and we can get in and out of it cool the next problem is
that we need to put some holes in it for things like data power and making sure
that the occupants can breathe now on the surface the data part is relatively
straightforward we obviously can't use copper wires so we'll be running fiber
optic cable easy what's not easy is that
we need to put it through a very specifically design designed hole called
a wave guide now clearly this hole is going to let some electromagnetic
radiation through like we can see light
through it for example but by making the length exactly four times longer than
the diameter of the hole we can stop any frequencies that have a wavelength a
quarter of the diameter of the hole which is good right yeah right because
they will reflect and bounce in the wave guide and cancel themselves out not
impressed yet now that you've got all the background let's do the demo from
the beginning again you can see here the chamber is working as intended nothing
is showing up on the Spectrum analyzer I stick my copper wire through here and
boom whole day ruined but if I take that
out and I put this plastic zip tie through here no problem at all I hope
yes so Fiber Optic Cables properly
engineered hole we got this with data taken care of now it's time to talk
about power and I got to confess I was
not sure how we were going to get AC power running in here without bunging up
all of our test results so let's take a closer look noting very importantly that
this is temporary these are just hacked up extension cables and our
electrician's going to come and run conduit from our panel back there over
to this box where the magic happens this
is basically a power filter on the electrical connection that goes into our
chamber uses a capacitor and an inductor that are spec to allow low frequencies
to pass through the 60 HZ AC from the wall but as the frequency increases the
capacitor and the inductor are going to clamp down and remove them making sure
that only the bits we want get through
finally we need to get some fresh air in here since sadly the lab isn't run by
robots yet and the way these work is
actually pretty similar to the wave guide that we showed you guys for the
fiber except instead of a small handful of holes it's many many holes don't
worry I got my prompter right here here so up here you're looking at a matrix of
hexagons that are stacked on top of each other that will prevent anything below
32 GHz from getting through this will be great for most of what we'll be testing
to start but seriously you guys are given us the upsell already we're going
to need to upgrade some of these components if we want to measure
millimeter 5G in the future assuming that anyone ever actually starts caring
about cellular signals that can be blocked by a piece of paper to recap
then we've got a steel box that doesn't let radio waves in or out that's good
but the problem is that if we just have normal steel walls inside the signals
will be bouncing around creating a bunch of modes and nodes or constructive and
deconstructive interference with those bouncing around there would be no way to
know if we were measuring the device itself or Its Reflection off the ceiling
or the wall or the floor or some combination of the three to stop our
test from interfering with our test then the walls are lined with these These are
carbon impregnated polyethylene panels from TDK that were imported all the way
from Japan how these work is that carbon is a conductor but kind of a bad one so
when the electromagnetic waves hit the carbon it creates an impedance and the
energy gets turned into heat now this does mean that we can't put any super
high power radio antennas in there the panels would either melt or light on
fire or maybe both but since there are no plans to run a local radio station
out of our RF chamber I think we should be okay all this effort will create a
quiet Zone in the middle of the room where we'll be able to accurately test
all kinds of things once our gear arrives specifically we're going to
start with phones using a fire cell 4G 5G lab kit that simulates a mobile
network for all you big nerds out there by the way the chamber was designed to
comply with I e299 just like this segue
complies with the association for Segway standardization
4.20 segue Raymond DMC once again again
huge thanks guys for getting us the RF chamber and look it has a floor now so
if you need a shielded enclosure EMC chamber and a cook chamber or any of the
parts that go into them they're super good at answering your questions they
even have mobile enclosures if you need RF shielding when you're on the go so
check them out down below if you guys enjoyed this video maybe you'll enjoy
the one on our first attempts to buy an RF chamber that is still garbage in our
warehouse thank you look at me I'm Pyramid Head gross