The antenna, made on the base of UA6AGW Antenna
(see References), was designed and build in
2017, at first at all for fixed and field operation. Author is
very appreciated to Andrey, IP50AA, for his very useful advices
on the antenna design.
Design of the Antenna:
Figure 1 shows design of the antenna.
It is a modification of UA6AGW antenna where horizontal radiators
are placed in vertical plane. To increase efficiency of the antenna
the main loop made of copper tube in diameter of 20- mm. Diameter
of the main loop is 800- mm. Variable capacitor C2 in 3- 30-pF
with air dielectric and gap between plates in 1.5- mm is switched
to bridge of the loop. Inside of the loop is placed a length of
a coaxial cable RK-75 in diameter of 10-mm.
(Note from I.G.:
It is possible to use any coaxial cable with outer diameter of
The braid of the cable is connected to C1. Central
core is not connected. The capacitor intended for initial tuning
of the loop to the 20 meters. In author design it was used high
voltage fixed capacitor in 10- pF. Vertical
radiators of the antenna made of aluminum tube in diameter of
20- mm and length of 2 meter each. Capacitors were installed
in waterproof plastic electrical box. Figure 2 shows the capacitors in
the box. Figure
3 shows main loop with capacitors' box. Figure 4 shows installed UA6AGW Antenna with Vertical Radiators in tested position.