It is not an
article, so it is early still to write scientific treatises on
this subject. It is while a test, supervision, analysis, searching
of answers to many questions. My experience can encourage ones,
and others I will disappoint. I think, a EH- antenna can compete
to any dipole, IV or GP, EH-antenna can
work both at a field, and at restricted urban conditions.
More info one
can find in the internet:
http: // www.eh-antenna.com/
the antenna is below.
But I have
done my own design that you can see on the pictures.
1 shows two antennas, conical one for 10 meters is made
by UA3AO, cylindrical antenna, retuning from
30 up to 10 meters is made by myself. I
have used two variometers from old military Russian surplus radio
R-140 for my antenna. The
variometer gives 0,65 - 6,9-microH or 2,8-29-mocroH,
it depends from the
Variable capacitors have max capacity of 55-pF. The cylinders
have diameter of 80-mm, height of 200-mm, and made of a bronze
sheet of 0,5-mm thickness. Using such
antenna details, it was possible to cover a frequency range from
10 up to 30 MHz.
If you have not such variometer, you can try to tune
the antenna to separately ranges. For example, for 20 meters:
L1=10 coils (3-microH), copper wire of diameter of 1.81-mm (#13
30 mm, L2=16 coils (6-microH)