Windom Antenna ~ "FD4/FD3" or a simple Off-Centre-fed Antenna

This antenna was my first antenna I ever setup when I got my license in 1994.

It is original 1/3+2/3 wavelength for 40 meter band. so 13.8 meter + 27.7 meter = 41.5 meter long. It is made to cover main bands 80 40 20 15 & 10 meter

Last years there been also modified versions to cover WARC bands 12, 17 & 30 meter.

Antenna height above ground tells you which balun to use:
30 to 60 feet (optimum performance) use Windom with 4:1 BALUN,           50>200 ohm         
60 to 70 feet, use Windom with 5:1 BALUN,                                                50>250 ohm          
70 to 75 feet, use Windom with 6:1 BALUN,                                              50>300 ohm  

There is different baluns to use:

Standard 4:1 balun on T-200-2 10-11 bifilar turns

Coreless balun. 4 equal lengths of RG213 makes a 4:1 balun

6:1 balun