- New antenna principle
- Small monoband antennas for shortwave
- Ideal for space restricted areas
- Unobtrusive, do not disturb the neighbors
- Effectiveness comparable to larger antennas
- High bandwidth
The design principle of the EH antenna has be discussed (often controversely) for some years. After many practical tests and positive findings of many amateurs these antennas are now available in a professional version for the ham radio sector.
EH antennas work differently than the known principle of the Hertz dipole. WIth a traditional Hertz dipole the E and H field components are not in phase, this effects that the radiation field is not properly built up until some distance (>1 wavelength). An EH antenna uses a phasing network to align the phase of both E and H field components, thus leading to a radiation field which is built up much faster and closer to the antenna. The net result are much smaller antennas with an effectiveness comparable to a usually larger dipole. Typical sizes are 2-3% of the wavelength.
EH antennas are mono band antennas, due to the design the entire band can be used. With it’s compact sizes the antennas can be easily used in space restricted environments, especially on the low bands like 80 and 160m. Additionally these antennas are comparatively quiet, reducing the often strong noise level on these bands.
The radiation pattern is not published by the manufacturer at this time. EH antennas are vertical antennas, so the azimuth diagramm is similiar to any omni directional antenna. The elevation diagram is comparable to that of any traditional vertical antenna, e.g. a quarter wavelength radiator with a gain of 0 to +2 dBD.
The connector is a PL female jack on the side of the antenna. The feedline is 50 ?, an antenna tuner is not required. Mounting hardware is provided for mast mounting.
To adjust the center frequency a simple alignment is possible. A copper belt can be adjusted in height on the antenna, influencing the center frequency on the band. A simple SWR meter is sufficient for this adjustment.
More information can be found at the patent holder for these antennas:
www.eh-antenna.com (english).
Short review of the 11m model from “Funk” 12/2003 (German, PDF, 68KB)
English review of the 80m model(English, PDF, 51KB)
English review from RadCom 9/03 (Englisch, PDF, 92KB Copyright Radio Society of Great Britain and reproduced with their kind permission.
English review from RadCom 8/05 (English, PDF, 375KB Copyright Radio Society of Great Britain and reproduced with their kind permission.
English user report on Venus 80 EH antenna
Test review from “Funkamateur 11/06” (German, PDF)
Type (Model) prices:
VENUS : 30/ 40 / 80 – 310 EU
COBRA: 10 / 11 / 15 /17 / 20 – 175 EU
ASPIS: 11 – 120 EU
ASPIS: 6 – 165 EU