Abstract: The present invention provides a system for determining the deployed length of a flexible tension element such as cable which is wrapped in a pack and fed through a funnel. The element may be sensed using different types of sensors such as optical, acoustical or magnetic sensors. A sensor is mounted in a funnel flush with the inside funnel surface. As wraps of the flexible tension element are deployed, or pulled off from the pack, individual wraps of the flexible tension element pass across the face of a detector as the flexible tension element is displaced in a generally circular pattern around the inside of the funnel. Signal processing circuitry produces a signal indicating the presence of the flexible tension element within a predetermined distance of the sensor.