Db is a comparison of the signal from a perfectly spherical pattern to
the pattern of an individual antenna. Think squshed doughnut. A 3db
antenna radiates a fat small doughnut while a 9db antenna radiates a
flattened and very wide doughnut. Same amount of dough just a different
shape.

The 9db can radiate further perpendicular to the antenna but if the
antenna tilts it radiates into the water or the stars. With the fat 3db
pattern some portion of the signal goes to the horizon no matter which
direction the antenna is leaning.

AP wrote:

What is this 3db,6db,9db etc.
Are the VHF antennas all the same? (excluding heght).
What db stands for??
Pls give me an idea.
tks
AP

"Sailman" wrote in message
om...

Assuming identical setups and a perfectly vertical antenna, what
percentage increase in range would be likely as a result of changing
from a 3db to 6db VHF antenna?




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