Crystals Go to War

While perusing the blogs of other amateur radio clubs around the planet, I happened upon a post about the development of crystal oscillators during World War II. This was one of the many technological developments that tipped the balance of the war. One link was to this (42 minute) 1943 video produced by Reeves Sound Laboratories about how crystals are used. If you follow this through to YouTube you'll find many videos on the development and use of crystals in oscillators, although you'll have to sort them from the spiritualist videos about the magical power of crystals.

Personally, I prefer to connect with the mysteries of the cosmos by contemplating the crystal's magical power of maintaining tight adherence to a given radio frequency on my journey to personal enlightenment.

The original blog post is the Crawley Amateur Radio Club Newsletter: Crystal Clear: The Struggle for Reliable Communications Technology in World War II, which highlights the book of that title written by Richard J. Thompson Jr.