Anybody Know Of Any Good Mu Metal Distrubutors? - Page 1
Forum section: electronics / projects

author: Lance
author_rank: Frequent Contributor
timestamp: March 06, 2011, 02:43:08 am
content: 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?

author: slburris
author_rank: Frequent Contributor
timestamp: March 06, 2011, 04:10:12 am
content: How about this at the Electronic Goldmine:http://www.goldmine-elec-products.com/prodinfo.asp?number=G16600AScott

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 06, 2011, 11:28:28 am
content: 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.

author: Unknown
author_rank: Unknown
timestamp: March 06, 2011, 11:31:25 am
content: I have used these guyshttp://www.lessemf.com/mag-shld.htmlin the past to shield a Hall effect sensor.

author: tyblu
author_rank: Frequent Contributor
timestamp: March 06, 2011, 07:29:10 pm
content: 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.)

author: Frangible
author_rank: Regular Contributor
timestamp: March 08, 2011, 08:11:46 pm
content: Talk about your high-tech foil hat!

author: Wim_L
author_rank: Regular Contributor
timestamp: March 08, 2011, 09:35:36 pm
content: Quote from: tyblu on March 06, 2011, 07:29:10 pmYou 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.

author: Lance
author_rank: Frequent Contributor
timestamp: March 09, 2011, 01:34:09 am
content: So it would be overkill for RF stuff? My brother wants to shield his wallet.

author: Wim_L
author_rank: Regular Contributor
timestamp: March 09, 2011, 03:16:18 am
content: 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.

author: Lance
author_rank: Frequent Contributor
timestamp: March 09, 2011, 05:44:29 am
content: Quote from: Wim_L on March 09, 2011, 03:16:18 amHow about copper then? Where can you go to get that?

author: the_raptor
author_rank: Regular Contributor
timestamp: March 09, 2011, 07:04:00 am
content: Quote from: Wim_L on March 08, 2011, 09:35:36 pmYeah 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

author: Wim_L
author_rank: Regular Contributor
timestamp: March 09, 2011, 02:01:45 pm
content: Quote from: Lance on March 09, 2011, 05:44:29 amLots 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).

author: sonicj
author_rank: Frequent Contributor
timestamp: March 12, 2011, 03:04:11 am
content: lol!http://difrwear.com/collections/all

author: osmosis321
author_rank: Regular Contributor
timestamp: March 12, 2011, 03:58:16 am
content: Shield it from what, exactly?

author: Lance
author_rank: Frequent Contributor
timestamp: March 12, 2011, 04:27:37 am
content: 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.

author: tyblu
author_rank: Frequent Contributor
timestamp: March 12, 2011, 04:41:56 am
content: surely the information is encrypted, though?

author: Lance
author_rank: Frequent Contributor
timestamp: March 12, 2011, 05:56:53 am
content: Quote from: tyblu on March 12, 2011, 04:41:56 amI don't imagine they'd be too hard to break.

author: tyblu
author_rank: Frequent Contributor
timestamp: March 12, 2011, 06:08:52 am
content: 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.

author: Lance
author_rank: Frequent Contributor
timestamp: March 12, 2011, 06:24:48 am
content: 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.

author: sonicj
author_rank: Frequent Contributor
timestamp: March 12, 2011, 08:23:30 am
content: RFID inside credit cards is retarded!the magnetic stripe seems very secure by comparison.-sj

author: the_raptor
author_rank: Regular Contributor
timestamp: March 13, 2011, 06:55:33 am
content: Quote from: tyblu on March 12, 2011, 04:41:56 amYou wish. A lot of the RFID cards just ping the same data that is on the magnetic strip.

author: Lance
author_rank: Frequent Contributor
timestamp: March 13, 2011, 08:57:58 am
content: Quote from: the_raptor on March 13, 2011, 06:55:33 amIf 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.

author: KJ6EAD
author_rank: Contributor
timestamp: March 14, 2011, 11:07:56 am
content: 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.

author: Lance
author_rank: Frequent Contributor
timestamp: March 15, 2011, 07:51:20 pm
content: Quote from: KJ6EAD on March 14, 2011, 11:07:56 amSounds simple enough, provided the light gets through the card.

author: kitkatbar
author_rank: Newbie
timestamp: September 21, 2012, 06:53:08 pm
content: Another place that can supply you with this information is the as follows:http://www.bwire.com/index.htmlTHey have been specializing in wire mesh for a long time and have recently broken into this new and growing field.

author: M. András
author_rank: Super Contributor
timestamp: September 21, 2012, 07:20:15 pm
content: 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?

author: TriodeTiger
author_rank: Regular Contributor
timestamp: September 21, 2012, 08:27:42 pm
content: Quote from: Lance on March 12, 2011, 04:27:37 amAny 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

author: SeanB
author_rank: Super Contributor
timestamp: September 22, 2012, 06:03:38 am
content: 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.

author: Smokey
author_rank: Super Contributor
timestamp: September 22, 2012, 07:33:11 am
content: 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.

author: G7PSK
author_rank: Super Contributor
timestamp: September 22, 2012, 09:27:56 am
content: Just put two pieces of tin can in the wallet one either side of the card, the rfid will not work on its edge.

author: Richardchris
author_rank: Newbie
timestamp: August 13, 2014, 05:56:30 am
content: WellAluminum foilis 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.