Homemade Diode

Soldier Picture:.
https://commons.wikimedia.org/wiki/File:Anonymous_soldier_with_a_foxhole_radio,_Anzio_Beachhead.jpg#filelinks.

Recommendations:.
http://www.electronicstheory.com/COURSES/projnkits/projDiode.htm.
https://en.wikipedia.org/wiki/Crystal_radio.

Razor Blade Picture:.

Products:
Razor Blade
Pencil Lead (Graphite).
Security Pin.
Timber.
Cord.
Screws.

Diode Picture:.
https://commons.wikimedia.org/wiki/File:Diode_Direction.svg.

This video clip demonstrates how to make a razor blade diode for a trench radio.