At third, to fasten with help of the cable ties the coupling loop
to the antenna loop at the distance of 4- 5- cm from the point
of symmetry of the antenna loop.
Tuning and Adjusting
Antenna is tuned to the working band with help of C2.
When horizontal wires are fully inserted (length is near 1.6-
meter) the antenna should tune with help of C2 to the range of
18.0- 29.0- MHz.
When horizontal wires are fully
opened (length is near 3.0- meter) and additional capacitor (length
of coaxial cable) is connected to bridge to C2 the antenna should
tune with help of C2 to the range of 14.0- 18.0- MHz.
Figure 10 Control Box
Antenna may be tuned to the working
frequency by minima SWR or maxima reception. As usual SWR is not
exceeded 1.5:1:0 at any band of operation of the antenna. Sometimes
changing form of the coupling loop (from circular to oval) may
help tune the antenna fine into resonance across the used bands.
When antenna is tuned and the
data for servo motor for every band is obtained and wrote down
at the servo tester the next re- tuning of the antenna is a very
simply. Just put the data to the servo tester press the control
knob and servo motor will tune the antenna.
11 Preparation of the Coaxial Cable for Coupling
(Please, read carefully instruction to the servo motor and servo
tester how they are working together.)
Antenna V. 20-10.51 is broadband. When antenna
is tuned to the center of the ham band (SWR is not exceeded 1.5:1:0)
the SWR at the edges of the band is not exceeded 2.0:1:0. However
sometimes at the 10- meter band it may be required fine tuning
of the C2 at the edges of the band.
Test of the UA6AGW Antenna V. 20-10.51
was tested at all working bands. Especially attention was brought
at the 20 meter Band.
Antenna showed very high efficiency. DD of
the antenna in the horizontal plane is almost circular. Difference
in DD across and along the horizontal wire is near 3- dB. There
were made lots QSOs with the antenna. Diploma “POBEDA” (Reference 5)
was made in three evening on the 20- meter Band with the antenna.