Anybody Know Of Any Good Mu Metal Distrubutors?

[Lance]

Does anyone know of any companies that sell mu metal foil in Canada or the US? I haven't had much luck finding a company yet.

I tried looking around on Digikey, but didn't find anything. I'm sure it's something they'd have though. Does anyone know where to look on sites like Digikey?

[slburris]

How about this at the Electronic Goldmine:

http://www.goldmine-elec-products.com/prodinfo.asp?number=G16600A

Scott

[mikeselectricstuff]

I have a vague recollection of reading that mu-metal's properties are severely reduced by any working, and that CRT shields are processed after being formed into shape to restore their properties - not sure if this is also the case with thin foil.

[Alex]

I have used these guys

http://www.lessemf.com/mag-shld.html

in the past to shield a Hall effect sensor.

[tyblu]

Hmm... good to know. May want to line kids' rooms with it (not worried about dangers of EMF, but having an electronics-free sleeping area --- yes... overly controlling, I know. will get over it.)

[Frangible]

Talk about your high-tech foil hat! 

[Wim_L]

Hmm... good to know. May want to line kids' rooms with it (not worried about dangers of EMF, but having an electronics-free sleeping area --- yes... overly controlling, I know. will get over it.)

You don't need it for high frequency electromagnetic waves. Copper mesh works fine. It's only for low frequencies that you need magnetic shielding too.

[Lance]

So it would be overkill for RF stuff? My brother wants to shield his wallet.

[Wim_L]

Yep. At radio frequencies, any good conductor will do. But take care with seams... Aluminium foil is suboptimal for this reason: surface oxidation ensures the seams will not allow the structure to work as a proper Faraday cage. Lots of overlap helps, though.

[Lance]

Yep. At radio frequencies, any good conductor will do. But take care with seams... Aluminium foil is suboptimal for this reason: surface oxidation ensures the seams will not allow the structure to work as a proper Faraday cage. Lots of overlap helps, though.

How about copper then? Where can you go to get that?

[the_raptor]

Hmm... good to know. May want to line kids' rooms with it (not worried about dangers of EMF, but having an electronics-free sleeping area --- yes... overly controlling, I know. will get over it.)

You don't need it for high frequency electromagnetic waves. Copper mesh works fine. It's only for low frequencies that you need magnetic shielding too.

Yeah people just need to look at their microwave. You can use plain ol' "chicken wire" to shield a lot of things (people were talking about using it against those crowd control RF "heat rays"). My uni has some kind of mesh to stop RFI in their computer labs and the bloody stuff is incredibly effective against cell phones. However the corridor outside the labs is oriented in the direction of the local cell tower, so you can get cell reception 50 metres down a corrider when you can't get it right next to the windows in the labs. So don't forget to shield the doors as well

[Wim_L]

How about copper then? Where can you go to get that?

Lots of places. For example, search for EMI shielding on Digikey. You can even get adhesive copper tape if that's convenient for you. Local construction or hobby stores might have cheaper stuff, so you might want to look around a bit.

Oh, and there are other options for magnetic shielding too. Know those thermally conductive pads to put between transistors and heatsinks? There are variants for shielding instead of heat transfer, and they include ferrite. One brand is Keratherm F. Not as good as mu metal, but it's flexible and easier to work with (I'd avoid using scissors on it unless you don't mind destroying them though).

[sonicj]

lol!

http://difrwear.com/collections/all

[osmosis321]

Shield it from what, exactly?

[Lance]

My friend wants to shield his wallet so people can't read his credit cards. A lot of credit cards have little RF tags embedded in them that allows wireless paying. You don't have the option to not have it. Anyone with a little know how could just walk around with a RF reader and scan the tags.

[tyblu]

surely the information is encrypted, though?

[Lance]

surely the information is encrypted, though?

I don't imagine they'd be too hard to break.

[tyblu]

Why is that? There are very good encryption schemes available to the general public. I had heard rumours that the information was not encrypted, though, which is scary. Can anyone confirm? I don't have an RFID reader with me.

[Lance]

Credit cards aside it's also apparently quite easy to read other things, like those RFID access cards. You don't even need all the data from it, just a valid pass code, so long as you have the site code.

[sonicj]

RFID inside credit cards is retarded!

the magnetic stripe seems very secure by comparison.
-sj

[the_raptor]

surely the information is encrypted, though?

You wish. A lot of the RFID cards just ping the same data that is on the magnetic strip.

[Lance]

surely the information is encrypted, though?

You wish. A lot of the RFID cards just ping the same data that is on the magnetic strip.

If that wasn't bad enough, chip and pin is also a complete push-over.

But getting back on topic, that's why I'm looking for shielding.

[KJ6EAD]

The card is vulnerable every time you remove it from the shielded enclosure to use it so why not just disable the RFID transponder system on the card and forget about shielding it? On my card I can easily identify the chip and it's antenna traces by shining a bright light through it. I can mark the location with a pen, then discharge a high voltage arc through it from a pair of electrodes, one on each side of the die. An expedient method would be to use the ignition coil lead on a car while cranking the starter or while it's running. Zap, zap, zap and it's done.

[Lance]

The card is vulnerable every time you remove it from the shielded enclosure to use it so why not just disable the RFID transponder system on the card and forget about shielding it? On my card I can easily identify the chip and it's antenna traces by shining a bright light through it. I can mark the location with a pen, then discharge a high voltage arc through it from a pair of electrodes, one on each side of the die. An expedient method would be to use the ignition coil lead on a car while cranking the starter or while it's running. Zap, zap, zap and it's done.

Sounds simple enough, provided the light gets through the card.

[kitkatbar]

Another place that can supply you with this information is the as follows:

http://www.bwire.com/index.html

THey have been specializing in wire mesh for a long time and have recently broken into this new and growing field.

[M. András]

i read it somewhere that rfid credit cards dont need authorisation below a certain amount of money so anyone who could acces a reader which used by shops can steal your money, stupid idea ever if something needs to work without physical contact why not make it secure ffs?

[TriodeTiger]

My friend wants to shield his wallet so people can't read his credit cards. A lot of credit cards have little RF tags embedded in them that allows wireless paying. You don't have the option to not have it. Anyone with a little know how could just walk around with a RF reader and scan the tags.

Any conductive surface of which will dissipate energy from the read field should reduce the effective reading range to a few millimetres, and a piece of tinfoil - or conveniently an aluminum surrounded card holder should be sufficient - why not test?

It appears the two VISA/Mastercard technologies use MIFARE under the "ISO/IEC 14443 Type A 13.56 MHz contactless smart card standard". http://en.wikipedia.org/wiki/MIFARE

[SeanB]

A nice copper sheet works well to shield the card. You need to make it so that 3 sides are soldered together so that the card slides in relatively easily. I keep a sheet like that in my wallet under the dards, even though none are RFID, just CNP only. A lot of merchants though are not using chip and pin, but chip, pin and sign.

[Smokey]

When I get a new credit card with the RFID chip in them, I just take a philips screwdriver and give the chip one good whack.  Works every time.  They never put it behind the magstip or anything important.

If you are actually interested in muMetal, then check out Eagle Magnetics. 
http://www.eaglemagnetic.com/
They do excellent work at good prices.   Unfortunately those good prices are still going to be too much to make a 1 off wallet though.  That stuff is expensive.  If you need low frequency shielding it's pretty cool.

[G7PSK]

Just put two pieces of tin can in the wallet one either side of the card, the rfid will not work on its edge.

[Richardchris]

Well Aluminum  foil is suboptimal for this reason area corrosion ensures the joints will not allow the framework to work as a appropriate faraday crate. Lots of overlap allows though.