I am aware of the repeating peaks at multiples of about 1360 Hz. You are probably aware that these peaks get smaller as the frequency rises, and are very small in the kHz range.
I would suggest that those who have access to an F-SCAN or F-SCAN2 do DIRPs on several different people in the range of, say, 300,000-600,000 with a delta of 1000. Have the subjects fast for two hours and remove electronic devices such as Cell Phone s and watches. Have them sit still during the DIRP. Turn off fluorescent lights. Compare the results of the various DIRPS.