FIELD: signalling equipment. SUBSTANCE: pickup has electro-mechanical converter, former connected in series with amplifier, Schmitt trigger, re-starting univibrator. Output of the converter is connected with input of the former through envelope detector. Output of the univibrator has to be output of the pickup. Electro-mechanical converter has frequency generator and capacitive divider, formed by capacitor and mechanical part, which is formed by two plates. The plates form electric capacity. Motionless plate is connected electrically with "earth" bus, and movable one is connected with one lead of the capacitor and with output of the converter. The other lead of the capacitor is connected with output of frequency generator. EFFECT: simplified design; reduced sizes of pickup. 2 cl, 1 dwg
