The "pulse" is the envelope of the RF energy. Lots of frequencies more like
white noise actually, start suddenly, trail off not quite so quickly.
Similar to a radar pulse. Two things. RF, pulse modulated.
Omnidirectionally radiated. Does that help?

--
Crazy George
Remove NO and SPAM from return address
"snarf" wrote in message
...
Without sounding like too much of a wise guy, please explain the single
electromagnetic pulse generated during a nuclear or other type of large
explosion.

Does a certain degree of oscillation (ringing) occur to explain the vast
distances travelled by what one would assume was a single large pulse?

Snarf


"Richard Harrison" wrote in message
...
Nic Santean wrote:
"-from "The Beginners`s Handbook of Amateur Radio" by Clay Laster, page
260."

Clay used many words to say the signal propagates too far to get back to
the radiator. It continues its journey away from the radiator.

Radiation is really caused by exchange of energy between alternating
magnetic and electric fields. They produce each other when they
alternate. Static fields don`t radiate. They soon fade away.

J.C. Maxwell speculated that displacement current produces the same
alternating magnetic lines as conduction current does. He was proved
right.

"Static" magnetic and electric fields move out into space when current
flows and charge builds. When they are no longer changing, the fields at
some distance have reached practical limits and stop expanding.
Alternate these fields, and the fields can build each other and travel
on and on.

Best regards, Richard Harrison, KB5 WZI