Abstract: An apparatus automatically determines the frequency deviation of a transmitter by analyzing a signal received from the transmitter. The apparatus automatically corrects the incoming signal for the improper deviation and maintains a record of the frequency deviation errors. Transmitters which consistently exhibit errors may then be recalled for servicing. This device increases data transmission reliability, improves compliance with FCC licensing regulations and reduces maintenance costs.

Abstract: An electronic security device includes an insulated loop shaped antenna which capacitively couples to any objects which intrude into a zone surrounding the antenna. The loop shape allows the antenna to be placed onto a doorknob of the room to be secured, and the insulation prevents electrical contact-bounce between the antenna and the doorknob. A detector circuit connects to the antennna and generates output signals indicating the amount of capacitive coupling. An alarm circuit connects to the detector circuit and sounds an audible alarm for a predetermined time interval when the coupling as indicated by the output signals implies that an object has intruded into the zone. A test circuit connects to the alarm circuit for temporarily decreasing the time interval of the alarm in response to a manually activated switch to allow the security device to be tested prior to being fully activated.