ZS6BKW (inverted-V)

The ZSBKW is a multiband wire antenna, working on 40/20/17/12/10 m without an antenna tuner. 80 m tunes very easily.

Antenna details:

  • length of the dipole: 2 x 14 m = 28 m (NYA rigid copper wire 1,5 mm2 H07V-U, cheap, used for electric installation)
  • length of the ladder line (450 Ohm wireman): 11 m
  • height above ground at the center: 11m (fiberglass tower)
  • height above ground at the sides: 4 m (steel pipes)
  • a cable choke is used for feeding the antenna, 2 m above ground

SWR is around 1:1.5 or less in the lower part of the resonant bands, it is around 1:2.5 in the upper parts. I will try to approach the lengths given by ZS6BKW (Rothammel gives: length: 27.51 m, 400 Ohm ladder line: 12.2 m, or length: 28.1 m, 300 Ohm ladder line: 11.2 m) to see whether this improves the antenna. Anyway, for the digimodes the antenna is quite optimal at the moment and it can be tuned for the upper parts with the bulit-in tuner of the FT-950.


  • Some pictures



  • Cable choke used for feeding the antenna (18.5 turns of Aircell 7 around a PVC pipe of 11 cm in diameter)