detector

electronic equipment that detects the presence of radio signals or radioactivity

• crystal detector — a detector consisting of a fine wire in contact with a galena crystal; acts as a rectifier
• scanner, electronic scanner — an electronic detector that scans automatically for some signal or condition

• electronic equipment — equipment that involves the controlled conduction of electrons (especially in a gas or vacuum or semiconductor)

• radio receiver, receiving set, radio set, radio, tuner, wireless — an electronic receiver that detects and demodulates and amplifies transmitted signals