Abstract: A broad-band antenna system capable of receiving VHF, FM, and UHF bands, having highly desirable directional properties, providing sharp nulls for the rejection of unwanted reflections, and with broad directional properties, usually obtainable only with large tunable dipoles or loops, many times the dimensions of this very compact antenna unit. This is strictly a receiving antenna, since it has no radiation capabilities, and consequently minimal loss of received signal due to reradiation.

Abstract: A simply installable, economical, room of a motel or hotel unit is provided in each room and an electrical device to be protected is connected to the room unit without the need for any modification of the device. The room unit is of sufficient sensitivity to sense various conditions indicative of an attempted theft, including the difficult to sense condition of cutting the power cord of the electrical device when the device is off. Each room unit is responsive to the detection of a condition indicating an attempted theft to produce a unique alarm signal which is coupled back to the AC power lines. The power supply lines of a plural phase AC power system customarily provided in the hotel or motel are used to transmit the alarm signals from the room units to receiving means for detection, and spare telephone lines which are customarily also available are used to transmit the detected alarm signals from the receivers to a central monitoring location.