Experimental Helical Antenna

for the 40- meter Band

Experimental Helical Antenna

for the 40- meter Band

By: Gennadiy Kuzmichyov, UN7FGO

My first helical antenna was made from a slinky coil (See: http://www.antentop.org/023/UN7FGO%20_023.htm) . Now I decided make antenna from a good copper wire. The antenna was my experiment in shortened helical antennas that may be only one antenna in strictly environment. I choose the 40 meter band as universal band for day and night propagation.

(You may found information on Helical HF antennas at: http://www.antentop.org/library/shelf_helical.htm)

For antenna form I used two plastic tubes in 32- mm (1.25 inch) diameter and in 1 meter length. Holes were drilled in the distance of 10 and 5 cm from the tube ends. Screws in diameter 4- mm were inserted in the holes. Antenna wire was attached to the screw. It was wound 20 meter of 1- mm (18-AWG) wire on the each tube. Between themselves the tubes were fixed by other plastic tube in diameter of 20- mm and in length of 20 cm. The small tube was easy inserted inside of the 32- mm tubes and may hold them firmly. Box near the antenna contains balun. Figure 1 shows the antenna design.

Figure 1 Helical Antenna Design

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