The following Spectrograms were ran using a McGreevy receiver in Sedona, AZ in 1999. The first gram is a line plot showing Russian Alpha transmissions plus a few unknowns at VLF frequencies. The second gram is that of a HAARP test. Note the 355 millisecond delay between the initial two transmitted pulses and their respective echoes. The delay indicates D-Layer reflection at an altitude of approximately 61 miles.
To listen to the Haarp test signal that created these Spectras click the Haarp Wave below.
Frequency Range: 1000 hz. to 12,000 hz.
Line Plot of the same Haarp recording.
