So, my Ê-1 with 40, 30, 20 and 17 meters bands was successfully assembled
and tuned. This one requires an antenna to go to the Air. Certainly,
an antenna is a simple thing if… if you live in a private house.
But I live in a multistorey apartment
building (made from concrete) with huge large restrictions on
installation of antennas. The result of these restrictions is
those, that I can install an antenna only at a window. Good sign
is that in mine apartment the windows are big sized- 150 to 210
My experience on the Air from such premises shows that in this case a
magnetic loop antenna is the most effective one. My first choice
was the antenna installed at the window. I already have bought
a hula- hoop (for antenna itself) and a small stool (for the base
of the antenna). However, after I have shown to my YL how the
antenna would be looked at its installation place a top of the
conditioner (buddy, it looks great!), my permission to antenna
installation inside room was rejected by my wife. No one of my arguments to
advocate the magnetic loop was accepted.
Other type of an antenna, which can effectively work in my limited conditions,
is a helical antenna. Some information on manufacturing and adjustment
of the antenna you can find in Reference
So, I began search for stuff for the antenna. Some days back I have bought
to my son a Magic Spring Spiral (DOLLARAMA, $1). This Spiral contains
96 coils, each coil has length of 11 centimeters, total
length of the wire is 1056 cm. Such length is perfect for helical
antenna for the 20 meters band. A wooden stick for open/close
curtains (DOLLARAMA, $1) was very suitable for form of the antenna.
The stick has diameter in ½” and length in 170 centimeters.
Design of the Helical Antenna: Photo shows the helical
at the window. At first three holes were drilled (one at up and two
down) in the stick. Copper wire in diameter of 18 AWG and 15 cm
in length was attached to the stick through
the holes. Helical antenna was hung up with the help of the wire
to an eave. Down part of the antenna was fastened by the wire
to a hook. Spiral wire was gone through another hole. Antenna
ground was connected to aluminum window frame. My window frame
was connected (it was prove by measurement) to the main “ground”
(green wire in the main).
Antenna at the Window
Magic Spring Spirale