Abstract: A motion detector having a motion sensitive switch, timing circuit, encoder and radio-transmitting circuit in a housing which may be affixed to a remotely-positioned article; and a decoding and receiving circuit housed in a second housing. The radio-receiving circuit receives the encoded transmitted signal and couples it to a decoding circuit; the decoding circuit is connected to a latch circuit which drives an alarm. The sensitivity of the alarm generation circuits are controlled by a timing circuit, and the alarm may be disabled in order to enable the operator to evaluate the nature of the incoming signals.