A measurement system for capturing a transit time, phase, or frequency of energy waves propagating through a propagation medium (702) is disclosed. The measurement system comprises two different closed-loop feedback paths. The first path includes a transducer driver (726), a transducer (704), a propagation structure (702), a transducer (706), and a zero-crossing receiver (740). The series and parallel resonance of the transducer (704) does not overlap the series and parallel resonance of the transducer (706). A second path includes a transducer driver (1126), a transducer (1104), a propagation medium (1102), a reflecting surface (1106), and an edge-detect receiver (1140). Each positive closed-loop path maintains the emission, propagation, and detection of energy waves in the propagation medium (702, 1102). In either path, a propagation tuned oscillator maintains positive closed-loop feedback of the system that sustains detection, emission, and propagation of energy waves or pulses in a medium.
