An antenna ball
or a corona ball
is a round metal sphere
usually attached to the free end of transmit
s, most often whip antenna
s. As the electric current
tends to a minimum at the end of the antenna, the voltage
tends to reach a maximum. Very sharp
features tend to result in very high electric field at those points; coupled with the high voltages at the end of the antenna, this can cause the air near the end of the antenna to ionize
creating corona. With sufficient transmitter power, this can cause the end of the antenna to melt
from the heat
. Placing a round object at the end of the antenna eliminates the sharp protrusion, and greatly reduces corona.
yep, those balls are there for a reason...