Turret Crystal Detector

A turret crystal detector (also called a multi-mineral or revolving-turret detector stand) was a practical design used in the wireless era (roughly 1910s–early 1920s), especially on ships and at land stations. Crystals (natural minerals such as galena, silicon, carborundum, zincite, bornite, iron pyrites, etc.) acted as primitive semiconductor diodes that rectified the radio-frequency signal so it could be heard in headphones. Sensitivity varied greatly from one crystal (or even one spot on a crystal) to another, and performance could degrade from vibration, handling, or atmospheric conditions. A turret held several different mounted crystals that the operator could rotate into position under the contact (often a “cat’s whisker” wire or another crystal) without having to change the entire detector. This was especially useful at sea or in commercial stations where rapid, reliable detection mattered.

Here you find 26 models, 24 with images and 0 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Kilbourne & Clark Mfg. Co.; Seattle, Washington