2 shows formulas to find the dimensions
of the parts of the antenna. To find the dimensions (in meters)
it needs the digit shown on the antenna parts to divide to the
central working frequency (in MHz). It works for coaxial with
shortening coefficient 0.66. For example, dimensions for antenna
for the 40- meter Band (central frequency= 7.09- MHz) should be:
72/7.09= 10.15- meter, 50/7.09= 7.05- meter, 22/7.09= 3.1- meter.
Antenna Strela may be placed horizontally
(preferably at height more the 0.25 lambda from the ground), may
be installed vertically or at some angle to the ground. Antenna
Strela may be installed similar to I.V. antenna. Stub for
the antenna should be made from the coaxial cable that is used
for feeding of the antenna. It is possible to use 50 or 75- Ohm
coaxial cable for the antenna.
Antenna is tuned to the resonance by shorten of the left
part and lengthen of the right part of the antenna.
for Photo: http://ric.cqham.ru/bigphoto.php?c=R3EC
Prototype of the antenna was made by UA4SZ for 2- meter
Band. Dimensions of the antenna: 49.5- 34.0- 15.0- cm. Antenna
was installed vertically at a window. The antenna worked great!
made the antenna for the 80- meter Band. The antenna Strela
was low- noise and very effective compare to usual dipole. Figure 3
shows parameters of the antenna at the frequencies from 3.5 up
to 4.0- MHz. At the figure Red color shows SWR Green color shows
R Blue color shows Z.