“After several attempts to build a multiband C-Pole I finally ended up with the Multiband H-Pole. C-Poles for different frequencies on one pole must be fed with separate feedlines over separate current baluns.
In a first attempt I fed the H-pole in the center with a ladder line. It was electrically no longer an “off-center-fed-dipole” as the C-Pole was, but a vertical, folded “doublet”.
The C-Pole is a resonant antenna, whereas the H-Pole is non resonant and must be matched with a tuner.
Construction and materials used for the H-Pole are similar to the C-Pole. I use non conductive glass fibre fishing rods, beware of conductive carbon fibre!
The first results are very promising. I had contacts with excellent signal reports within a few minutes on all bands except 80m at @ 12:00 UTC in July 2008.
I used the SG-239 Automatic Tuner (asymmetric !). So far, the sound of the automatic tuner, was “healthy”, only a few “clicks” and down was the SWR! I connected the lower half of the H-Pole to the ground connector, the upper half to the “hot” side of the tuner output.”
Elevation Diagrams H-Pole [black] Versus C-Pole [blue], 0.5m over MININEC-Ground, 20m-Band
The Azimut Diagrams for both antennas are omnidirectional
See EZNEC-File: multi-h-pole-tl.ez
This kit has been designed by David Bowman G0MRF and contains all the parts required to drive a PA on 2.4 GHz for QO-100. The completed board will hav... Read more