Here we see a Cuban jammer trying to take out the American Radio Marti broadcast. The little puffy dots are pulses occurring over most of the voice range, and the red blobs indicate that most of the energy is concentrated in the fundamental speech spectrum of 250 to 1000 Hz. The flat line at 5 kHz is adjacent-channel heterodyne with another station.
The jamming is seen by itself at first, then voice syllables occur at 1, 1.6, and 2 seconds. They can be seen, and heard, quite well under the jamming, and in fact Marti was almost completely intelligible on this occasion. The recording, however, was made in the western U.S., far from the Cuban target area.
All plots made with GRAM.EXE.