Why can’t I just turn off my phone?
Yes, of course you should but nowadays we can’t really say any more if a phone is actually turned off when you power it down. The alarm still works, right? Also, you can’t take out the battery any more of most current devices. Read this to get an idea what s going on.
Does the pouch work?
Yes, it does! It works very well for a whole bunch of frequencies depending on which material you got. If you want to make sure it is also strong against close up wifi signals I recommend sewing a double layer pouch. Test it!
How does it work?
The material is a copper or silver coated cloth or fleece especially developed for electromagnetic protection. As a pouch it forms a Faraday cage which blocks all eleoctro magenetic radiation (radio waves). Usually it is used in military or aviation . When you sit next to a strong radar antenna you better want to isolate the wall to not get grilled.
Does the material also shield RFID chips in passports?
Yes, it does. Since the RFID ships are usually powered passively the signal strength is much lower. RFID is in general much easier to kill than GSM and other signals.
Where to get the material?
Search for RF Shielding Fleece, HF+LF Shielding Fleece, RF Shielding Cloth, Electromagnetic Field Shielding Fabrics or Metalized Fabrics ! You will find these and similar materials in stores which are into electromagnetic protection. The fleeces usually have the best absorbing properties but cloths work as well. Everything with 99,999% damping for 70dB and higher (for a broad range of frequencies 1-5Ghz) should work very well. There are many different online shops offering these products. Some examples below. If you find a good supplier in your country please let me know, I ll add links below… Example shops:
[via Aram Bartholl]