Picture 1
This is a pulse train preceded by an unusual broad pulse. The pulse train has a pulse frequency of about 10 hz. This time the leading broad pulse is just a broad pulse, lasting 0.05 sec. (see Picture 2). Any of the regular pulse is narrower and lasts about 0.01 sec, or 5x less (see Picture 3).

Picture 2
Magnification of 0.6 s region of Picture 1.
sample 8 (1s, 8 kb mp3) a leading single broad pulse (0.06 sec).
Closeup of the broad pulse leading the main pulse train. This pulse is quite broad, lasting 0.05 sec, and does not resolve itself into a pulse train, even under higher magnification.

Picture 3
Magnification of 10.75 s region of Picture 1.
sample 9 (3.5s, 29 kb mp3)regular pulses (0.01 sec each), including the 2 illustrated here.
Closeup of part of 2 pulses from the regular pulse train. This shows that regular pulses are about 0.01 sec wide.