The thin Mylar works because the cell signal is not very strong.
Mylar will not work on a sat phone because the signal is much stronger. Been there. Tried that. Several layers of tin foil (a stronger barrier) will shut off a sat phone.
Mylar will not work on a sat phone because the signal is much stronger. Been there. Tried that. Several layers of tin foil (a stronger barrier) will shut off a sat phone.
Coincidentally we just tried this experiment over the weekend with a new droid smartphone - wrapped it up, folded over the ends, about 6 layers of aluminum foil. Call from a Blackberry did not go through, but call from an iphone did. We'll keep experimenting though...