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The experimental difficulties associated with recording the frequency spectra of ultrasound pulse-echo signals are discussed. In particular, the most troublesome sources of synchronous and asynchronous noise are reviewed. A simple interface circuit for XY chart recording of these frequency spectra is presented. We discuss its major advantages over conventional Polaroid hardcopy recording. These include its ability to discriminate against both synchronous and asynchronous noise and its ability to record multiple spectra on the same XY chart. A detailed discussion of our spectral amplitude calibration procedures is also included.