Abstract: A system and method for determining the location of faults in a telephonic distribution system where each endpoint in the system has an associated verification code. The endpoints are polled and the response is compared to a corresponding verification code in memory. When the response does not match the verification code in memory the result is included in an endpoint map. An analysis is then performed to identify faulty elements in the system which are reported with their geographical location coordinates.

Abstract: A digital video quantizer for use in TCAS and ATCRBS/SIF systems. A digital delay receives a digitized video signal and produces a plurality of delayed digital signals which are used throughout the quantizer. A threshold generator then produces a predetermined threshold and a dynamic threshold, and a quantized video generator compares one of the delayed digitized signals to a threshold to produce a quantized video signal. A slope quantizer detects a slope of the digitized signal which exceeds either a positive or negative threshold. In addition, a rise time detector detects an excessive rise time in the digitized video signal, and a chip amplitude comparator provides a signal which is used in detecting Mode S data bit values. The digital video quantizer's use of digital references rather than analog references, eliminates the inaccuracies caused by a reference voltage varying over time or temperature. The digital references also facilitate modification of the reference values at a later time.

Abstract: A range processor for airborne distance measuring equipment in which coherency of reply signals from the ground based DME station is determined by incrementing the contents of storage locations of a random access memory device for each reply signal according to the time of reception of the reply signal and for decrementing the contents of the storage location if no reply signal is received. Whenever the contents of a storage location exceeds a threshold value a range gate is generated so that the next reply received within the range gate causes the time of reception of the reply to be stored as range data.

Abstract: A thermometer suitable for a hot tub, spa, pool, and the like, and including a temperature sensor and indicator and a light source so the indicator can be read at night or in dim light. A tubular configuration which hangs upside down in the water when measuring temperature, and which is manually turned upright for reading, with an orientation sensitive power supply for energizing the bulb when in the upright position. A battery operated power supply which is permanently off or open circuited during shipping and storage and which is activated by the user by simply ramming the cap down on the unit to electrically bridge an open circuit in the lamp supply circuit.