Its two approximately five-eighth-wave legs produce narrower major lobes than a half-wave dipole.
Antennas · F1SYH
Extended Double Zepp
The Extended Double Zepp, or EDZ, is an approximately 1.25-wavelength wire antenna providing bidirectional gain.
HF
EDZ
Gain filaire
Operating principle
Main characteristics
Typical gain
Environ 4 à 5 dBi selon hauteur
Impedance
Élevée
Polarization
Horizontale
Difficulty
Intermédiaire
Dimensions and design
Each leg is approximately 0.625 wavelength. Balanced line and a tuner are normally used.
Construction and tuning
Step 1
Calculate two five-eighth-wave legs.
Step 2
Install the antenna as straight as possible.
Step 3
Use balanced feed line.
Step 4
Avoid severe bends.
Step 5
Match with a balanced tuner.
Step 6
Orient the wire perpendicular to desired directions.
Advantages
- More gain than a dipole.
- All-wire construction.
- High efficiency.
- Useful DX lobes.
Limitations
- Large span.
- High feed impedance.
- Narrower pattern.
- Requires a tuner.
History and origin
The EDZ evolved from Zepp antennas and research into long gain dipoles.
Safety
Feed line and wire ends carry high RF voltage.