Abstract: The methods and apparatus disclose a signal processing system acquiring the half-period and magnitude of the highest frequency component at any one time of an analog signal. Two comparators compare positive and negative going slopes of the signal to respective out of phase versions of themselves. Maxima and minima are detected by the respective comparators to set and reset two timers. The timers time the lengths of the positive and negative going slopes between the maxima and minima. An analog to digital converter converts the magnitude of the signal at the maxima and minima. A microprocessor stores the times and magnitudes in a memory and is in a second embodiment adapted to determine the individual frequency components of the signal from the stored values. The acquired values may be transmitted in digital form or may be reconstructed for analog transmission.