Introduction to VLF radio emissions
There are two types of VLF emissions;
natural and artificial. The earth, out of all the planets in the
solar system happens to be a great source of both. Thunderstorms are
a major contributor to earth's natural resources and they happen to
be the starting place of natural VLF radio emissions. Artificial
emissions come from man-made things; radio communication
transmissions, generating stations, power distribution networks,
high power devices running on AC power.
Listening to VLF radio emissions
Unless you live in a remote wilderness area,
natural VLF radio emissions are not heard without some effort and a
lot of patients. The avid hobbyist must get out and away from the
city. Every town, big or small has an electrical distribution system
called the AC power grid. The AC power grid is a menace to VLF radio
enthusiasts. The constant drone of the 60 cycle oscillation can
drive the average person / listener insane! A tolerable site would
be found at least one mile from the nearest power line or source.
The ideal site would be tens of miles away from the nearest man-made
electrical AC (alternating current) power source or transmission
line. Keep in mind that underground power lines are just as
intimidating as above ground lines - maybe even more because they
are unseen.
Lightning is dangerous!
NEVER under any
circumstances set up a VLF station in a thunderstorm! One small
fraction of a second is the time it takes for lightning to travel 15
miles through the air to YOUR
VLF antenna, down the wire connections, and striking
whatever conducts electricity. Humans (that means YOU!) are very
conductive because of the water and salt content in the body. A
single strike discharges more than a BILLION watts of electrical
energy in a split second - nobody in their right mind would want to
be near such an awesome and unyielding event.
If a storm happens to sneak up on your location without warning,
the best thing to do is drop everything and seek shelter. A safe
place would be inside a vehicle. If the entire VLF receiver station
can be disassembled in less then 30 seconds then it might be ok to
break it down and bring it in. The serious VLF listener would have a
very hard time packing up the station in under 30 seconds. A plan of
action wouldn't be a bad idea for the unexpected catastrophic event.
It might be a good idea to think about remote VLF listening for high
lightning incidence areas, such as in the state of Florida and other
places in the world. Listen to your national weather service
bulletins the day before going out into the field.
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