crystal set

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crystal radio receiver

Wikipedia

crystal set (plural crystal sets)

(electronics) An early radio receiver, having no electrical power supply except the radio waves themselves; it used a crystal of lead or cadmium sulphide and a wire (the cat's whisker) touching the crystal's surface.

an early kind of radio receiver

Catalan: ràdio de galena f
Chinese:
Mandarin: please add this translation if you can
Danish: krystalapparat n, krystalmodtager c
Dutch: kristalontvanger (nl)
Finnish: kideradio
French: récepteur à cristal m, poste à galène (fr) m, poste de radio à cristal m
German: Detektorempfänger m, Detektorradio n
Italian: radio a galena f
Norwegian:
Bokmål: krystallapparat n, krystallmottaker m

Nynorsk: krystallapparat n, krystallmottakar m
Portuguese: rádio de galena m
Russian: дете́кторный приёмник m (detéktornyj prijómnik)
Spanish: radio a galena f
Swedish: kristallapparat c, kristallmottagare (sv) c
Volapük: kristadaparat