LEARNING BY DOING
Wire Antennas + Local Parks + Elmers = Shared Knowledge & Experiences
LEARNING BY DOING
Wire Antennas + Local Parks + Elmers = Shared Knowledge & Experiences
OBJECTIVES FOR WIRES IN THE PARK (WITP)
WITP fosters learning by doing. Through WITP events, experienced amateur radio operators have more opportunities to step-up and become Elmers for the newer amateur radio operators, while the newer amateur radio operators have more opportunities to ask questions, gain knowledge, and practice skills.
WITP events and activities focus on getting amateur radio operators out of their shacks and into local parks to use their collective knowledge and experiences to design, make, install, and test temporary field antennas .
Basic WITP Antenna Types
Dipole Antennas
Resonant Loop Antennas
Monopole Antennas
A dipole wire antenna is the simplest type of radio antenna, consisting of two conductive wires whose collective length is half the length of the maximum wavelength the antenna is to operate. This antenna is fed by the transceiver at a midpoint point where the two wires intersect, which is inherently at an impedance close to that of the feedline.
Dipole antennas are typically mono-band, but can be made to be multi-band through the use of coils, multiple wires, or by offsetting the feed point between the dipoles.
Monopole Antennas
Resonant Loop Antennas
Monopole Antennas
Unlike the dipole antenna, which is fed at a midpoint of a half-wavelength wire, monopole antennas are fed at one end of the wire. This feed point at the end of the monopole antenna is at a very high impedance compared to the feedline from the transceiver. Consequently, monopole antennas require an impedance matching device to function correctly.
Monopole antennas are inherently multi-band when operated at the harmonics of the lowest design operating frequency.
Resonant Loop Antennas
Resonant Loop Antennas
Resonant Loop Antennas
Resonant loop wire antennas have a perimeter close to one wavelength at the operating frequency, which makes them self-resonant. The feed point can be at various locations around the perimeter of the loop.
Loop antennas may be constructed in many forms including horizontal loops in square, rectangle or triangle (delta) shapes. They can also be in the vertical plane and are most often in the same shapes with the delta being very popular as it has both vertical and horizontal polarization.