At second, find
the point of symmetry of the coupling loop. The coupling loop
is mounted in the top of the antenna loop. Point of symmetry of
the coupling loop should concur with the point of symmetry of
At third, to
fasten with help of the cable ties the coupling loop to the antenna
loop at the distance of 6-8- cm from the point of symmetry of
the antenna loop.
Picture 6 shows the Field Antenna UA6AGW
V.40.21. Antenna UA6AGW V.7.01 (horizontal wires are down) is
seen on the background.
to the resonance by capacitor C2. In receiving mode the antenna
is tuned by maxima reception. In transmitting mode the antenna
is tuned by maxima RF- Voltage at a horizontal wire. Picture 7 shows parameters of the antenna measured
by Antenna Analyzer AA-330M. Pass Band of the antenna at SWR 2.0:
1.0 is 90- kHz. However in the field conditions when capacitor
C2 is accessible the antenna may be easy to retune.
UA6AGW V.40.21 was tested in the Air at height 6 and 4- meters
above the ground. The antenna was compared with Antenna UA6AGW
v.40.02 (Reference 1) installed on 7- meter mast. Antenna UA6AGW V.40.21 was
tuned to 7120- kHz. Antenna UA6AGW V.40.02 was tuned to 7110-
6 Field Antenna UA6AGW V.40.21
Test at 6-meters height.
Antenna UA6AGW V.40.21 is low noise compare to Antenna
UA6AGW v.40.02. Picture
8 shows screen shot SDR transceiver with Antenna
UA6AGW V.40.02. Receiving signal is near minus 120- dB. Ratio
S/N is near 10- dB. Picture
9 shows screen shot SDR transceiver with Antenna
UA6AGW V.40.21. Receiving signal is near minus 120- dB. Ratio
S/N is near 15- dB. The picture is taken
at day light time with minimal time tag.