[Antennas] The Top Hat?
Robert Lay (W9DMK)
[email protected]
Thu, 2 Oct 2003 22:20:19 -0400
The top hat has been around since the beginnings of radio.
The idea is that the spreading fronds of the top hat provide the same effect
as a capacitor connecting back to earth. The capacitance to earth being
higher that it would have been otherwise from that point on the antenna
typically causes the system to be closer to resonance for an otherwise short
antenna. That brings the current flow in the antenna to a higher level than
it would be otherwise - thus providing greater signal strength all around in
the horizontal pattern.
Look ma, no math!
Bob Lay (W9DMK) in Dahlgren, VA
http://www.qsl.net/w9dmk