Abstract: Monitoring apparatus including an unmodulated radio-frequency transmitter carried by or affixed to the person to be monitored and receiver/monitor apparatus at a monitoring location for providing quantized visual and audible indicia based on received signal strength. The receiver AGC level, being a function of received signal strength, provides the variable which determines the repetition rate of tone bursts and the number of LED bar visual indicia lighted within an array of such LED bars. The response levels of those indicia are then a function of the distance between transmitter and receiver. Movement of the child (for example) beyond a predetermined range is immediately detected by a person at the receiver location. Circuitry is provided for presetting the maximum allowable range before alarm is instituted.