The radio is tuned only to receive a specific frequency.
That pulse is composed of many frequencies. Frequency that
interferes with radio reception is a unique sine wave
frequency
within that pulse. Just one of so many frequencies that
create the pulse. Pulses - like all waveforms - are a
summation of basic sine waves at different frequencies,
amplitudes, and phases. The radio does not receive a pulse.
It receives only parts of a waveform that are specific to its
tuned frequency. Fourier analysis demonstrates the concept.
The radio does not receive a pulse so much as it receives one
frequency that was part of that pulse.

A chart for the frequency spectrum of lightning is available
in:
http://www.hubersuhner.com/products/...kb-bas-fre.htm
..

What does DC arcing create? That was how radios worked.
Sparking DC electricity created AC electricity that resulted
in radio waves. Telsa did not transmit DC electricity. To
perform electricity transmissions, DC electricity was
converted to AC. DC arcing is detected how? By measuring AC
components created by that arcing.

Meanwhile TimPerry repeatedly refers to DC pulses. That
would be DC analysis. Lightning pulse is AC electricity. It
creates electromagnetic waves of same frequencies. You even
have a chart for that frequency spectrum. What the chart does
not show is how the energy content quickly tapers to zero as
frequency approaches DC. That pulse called lightning is
composed of electricity at RF frequencies.

CJT wrote:
w_tom wrote:
... Lightning is RF electricity. That RF energy is why
lightning even causes noise on radios. So now you say
all those RF sine waves, demonstrated by Fourier
analysis, really do not exist?

You're demonstrating a basic lack of understanding of
Fourier analysis. Fourier used the sine function as a
basis function. That doesn't mean there are sine waves
"in" the pulse. If he had used some other set of basis
functions, would that "prove" that those other bases were
present in the pulse?

Don't get me wrong -- I'm ok with you saying there's RF
energy in the pulse, but not with your extrapolation to
"RF sine waves." We're talking about impulses here.
...

The radios are responding to the pulses. Fourier series are a
useful way to analyze the response. But the radio is essentially
a filter that alters the signal it sees. It's not locking on to
some RF sine wave as you seem to think.
...

Huh? Have you seen those videos of (as I recall) DC arcs in
high voltage transmission tests that are floating around the Web?