In the far
90s it was installed and tested several outdoor HF helical antennas.
About two designs of the antennas is the article. The antennas
were mounted on the clothes drier installed at the first floor of the 9
story building. Height from the ground to the clothes drier was
near two meter.
Helical HF antenna for the 40- meter Band
was installed on the clothes drier and was placed near 70 cm out
of the concrete wall of the house. Form of the antenna was made
from wooden sticks. The sticks were fixed by the nails to the
wooden triangles. Each side of the wooden tringle had length of
30- cm. Length of the sticks was 2.3- meter.
of the helix form was defined by the length of the window where
the wooden form was mounted. Stranded copper wire in 40 meter
length and in 1- mm diameter (18- AWG) was wound above the form.
Window Clothes Drier
Wire in 3-
meter length going from the helix to transceiver and wire in 1.2-
meter length going from the helix to the capacitive load as well
was included to this length. Figure
1 shows design of the Window Mounted Helical Antenna.