Spurred on by the wisdom that my biscuit tin might not be a perfect keysafe after all I tried a Bacofoil lightweight alternative.
Folding a single layer of foil over the fob much like slipping it into a thin alloy pitta bread saw the fob still able to open the van however simply sealing the edges of the foil Cornish pasty style stopped the fob working even alongside the van.
Transferring this effect to the biscuit tin is difficult as it's impossible to press the plipper without partially removing the lid and that allows the RF to escape.
To my mind as long as the biscuit tin lid is making contact pretty well all around the rim then the RF should remain captive within... think of it as longer wavelength visible light escaping from an illuminated lamp inside the tin and the Faraday biscuit tin is more plausible.
Folding a single layer of foil over the fob much like slipping it into a thin alloy pitta bread saw the fob still able to open the van however simply sealing the edges of the foil Cornish pasty style stopped the fob working even alongside the van.
Transferring this effect to the biscuit tin is difficult as it's impossible to press the plipper without partially removing the lid and that allows the RF to escape.
To my mind as long as the biscuit tin lid is making contact pretty well all around the rim then the RF should remain captive within... think of it as longer wavelength visible light escaping from an illuminated lamp inside the tin and the Faraday biscuit tin is more plausible.