The antenna works with good SWR at the frequencies
3.500- 4.000- kHz. All antennas, what I made before (there were
I.Vs., dipoles and slopers) did
not work at such wide band. The antenna has input impedance 75-
Ohm. It allows use a chip TV coaxial cable for the feeding of
the antenna. The 75- Ohm coaxial as usual is matched well with
the 50- Ohm output of the transceiver. Figure
1 shows the design of the antenna.
It is a slope stub antenna. The antenna may be placed
at 30- 60- degree to the horizon.
Antenna has two radials (more radials are better)
that are placed at 120- degree to each other. Antenna has input
impedance (at terminals x-x1) close to 300- Ohm. A lambda/4 length of a 150-
Ohm coaxial cable does match the input impedance with the feeding
coaxial cable. Instead of the cable it is possible use a transformer
1:4. The antenna wire is connected to the ground. So the antenna
is low noise at reception and lighting protected. Antenna may
be recalculated for other bands.