A protective measure to protect electronic devices from the effects of EMP include the Faraday cage.
(Update) The effectiveness of protection depends on several complicated factors including strength of EMP, your geo location from it, EMP altitude, and the gauge and type of metal you are using, and more… Suffice it to say that any makeshift Faraday Cage is better protection than none.
Build a simple Faraday cage from a small metal garbage can and lid.
The lid must fit snugly over the can. If the lid does not make good metal-to-metal contact, the open area could allow EMP to damage your equipment.
To further protect your equipment, purchase a metal screen about 6 inches wide and as long as the circumference of the can. Fold the metal screen in half, length wise, and then place it around (and fold over) the lip of the garbage can. The lid should then fit snugly against the screen and can, protecting all equipment contained inside the can.
Any metal can act as a Faraday cage. Even an ammo can. However, good metal-to-metal contact is imperative.
Remove all gasket material from the lid. If the can has been painted, make sure to remove the painted area around the lid where it contacts with the can itself (and the inside of the lid) with sand paper, so as to make good metal-to-metal contact.
An electromagnetic pulse (EMP) attack on the American homeland is one of only a few ways that the United States could be defeated by its enemies — terrorist or otherwise. And it is probably the easiest. A single Scud missile, carrying a single capable nuclear weapon, detonated at the appropriate altitude, would interact with the Earth’s atmosphere, producing an electromagnetic pulse radiating down to the surface at the speed of light. Depending on the location and size of the blast, the effect would be to knock out already stressed power grids and other electrical systems across much or even all of the continental United States, for months if not years.
Having said that, it may be prudent to protect some electronic items that may be useful post-collapse. Portable AM/Shortwave Radios. 2-way communication radios. Portable solar battery charger. The list can be as long as your imagination…