EFHW antenna designer

Design an End-Fed Half-Wave (EFHW) antenna, in either an inverted-L or inverted-Vee form, using a single main support. This type of antenna is designed for one principal amateur HF band, usually 80 meters or 40 meters, but typically displays VSWR minima on several higher bands, and can therefore be a good multi-band antenna. Being an end-fed (high voltage feed-point) antenna, it is most often matched using a 49:1 unun.  Read more...

Set antenna color:    

Principal band
Frequency: kHz    ?
Antenna length: m
Antenna configuration
Configure as:
Antenna wire
Diameter: mm
Support pole
Height: m (At support point)
First antenna section
Length: m
Angle: Angle from vertical: °
Second antenna section
Length: m
Angle: Angle from horizontal: °
Counterpoise (radial)
Length: m
Inductance load
Value: µH    ?
Position: m above foot
Antenna overview
Section #1 Section #2
Length Angle Length Angle
Press the "Show antenna" button to display your antenna
configuration here in interactive 3D graphics mode
Antenna feed-point:    Inductance load:

Antenna performance

Here you can generate plots of radiation patterns, VSWR chart, antenna currents diagram and Smith chart for your antenna over a choice of ground types. By changing the physical dimensions of the antenna, and refreshing these plots, you can learn a lot about how such antennas will perform in the field.
Please note that radiation patterns are here modelled over flat ground - when the antenna is erected on a hill-top or mountain summit, the surrounding sloping ground will generally cause angles in the elevation radiation pattern to be lowered in the direction of the slope: the steeper the slope, the lower the effective elevation take-off angle will be, and the better the chances of making long-distance contacts.

Choose ground type of
land in the vicinity
of the antenna:
   Conductivity: S/m    Dielectric const.: F/m
View radiation patterns:    Set elevation angle for azimuth plot:  °    ?
Set azimuth angle for elevation plot:  °    ?
Radiation patterns for: ?

View VSWR chart: Check on:   From:To:
Display impedance curves: Using unun   
Impedance curves scales:   
Effect of coax on VSWR: Coax length: Type: ?
  Show coax losses as: 
View currents diagram:
View Smith chart:
Antenna gains
at 0° elevation:
Antenna impedance:
Frequency range: