01- 2017, # 021
UR0GT Helical Antenna for the 40- meter Band
Antenna for the 40- meter Band
The publication is devoted to the memory
Credit Line: Forum from:
Nikolay (UR0GT) would like experimented with Helical Antennas for the
HF Band. He already made a MMANA model of the Helical HF Antenna
for the 40 meter Band. But…did not have time… he lived for us just
two files of the antenna.
1 shows design of the Helical Antenna for the 40- meter Band. The antenna is a typical shortened Helical
Antenna with height 4.7 meter. Diameter of the antenna is 14 cm.
Antenna contains 59 turns of coper wire. Nikolay, UR0GT, made two
files of the antenna.
Now I play with UR0GT File
of the Helical Antenna. It was very interesting for me that the
MMANA confirmed some of my practical research.
For example, I found on practice
that the frequency of the second resonance of the Helical antenna
is slighter higher the double frequency of the first resonance.
MMANA gives second resonance for the antenna at
15.371 MHz that is higher the 14.100 MHz.
I found on practice that the third resonance of the Helical Antenna
is slighter higher the sum of the first and the second resonance
of the antenna.
The two MMANA models of the UR0GT Helical Antenna for
the 40- meter Band may be loaded: http: // www.antentop.org/021/helical_ur0gt_021.htm
One file for antenna wound by wire in diameter of 2-
mm (12 AWG) another file for antenna wound by wire in diameter of
0.6- mm (23 AWG). Files for the Helical Antenna
were simulated in MMANA. At the simulation was used parameter “Real
Antenna wound by wire in
diameter of 0.6- mm shows best SWR but worst gain compare to the
antenna made by 2- mm wire. The MMANA File of the Helical antenna
allows to play with different ground or counterpoises, the file
may be scaling for other bands and so on..
Figure 2 shows Z of the Helical Antenna
for the 40- meter Band wound by wire in diameter of 2- mm. Figure 3
shows SWR of the Helical Antenna for the 40- meter Band wound by wire
in diameter of 2- mm. Figure 4 shows DD of the Helical
Antenna for the 40- meter Band wound by wire in diameter of 2-
73! Nick, UR0GT
Note from VA3ZNW: On my experience the input impedance and in
some cases the resonant frequency of the Helical Antenna is very
depend on the real ground or counterpoises used with the antenna
and to the nearest objects. I experimented with Helical Antennas
(in the ends 1990s- beginning 2000s) but did not simulate the
antennas in MMANA. My book based on my experimenters with Helical
Antennas (in Russian) is published at:
The model has third resonance
23.078 MHz that is higher the 7.05 + 15.371= 22.421. However, anyway
the high resonances depend on the antenna design and lots of different
Figure 1 UR0GT
Helical Antenna for the 40- meter Band