Figure 2 Capacitors Inside of Waterproof Electrical Box
The antenna is fed through
a Coupling Loop in diameter of 430- mm. Figure 5 shows the coupling loop
at the main loop. References
give your information how to make the coupling loop. It is possible
use just several pieces of wire instead of the lower vertical
The antenna is tuned
to the resonance frequency with help of capacitors C1 and C2.
To the minimum SWR in coaxial cable the antenna tuned by changing
distance between coupling and main loop and may be by changing
the form of the coupling loop. Figure 6
shows SWR and Z of the UA6AGW Antenna with Vertical Radiators installed
at distance of 0.5 meter between the ground and the end of the
lower vertical radiator.
DD of the UA6AGW Antenna with Vertical Radiators:
As you can see from Figure 6 the antenna has SWR no
more the 2.0:1.0 at all 20- meter Band. Practice shows that the
antenna has almost circle diagram directivity in horizontal plane
with low radiation angle in vertical plane. Antenna may be placed
at small height above the ground.