Compare to 2-5/8 and 3-5/8 collinear the Two Elements
YAGI has more gain. Experience shows that the more distance between
radio stations the more Two Elements YAGI beat the collinear.
My Two Elements YAGI has room near 100-centimeters x 40 centimeters.
Collinear antenna that has close to the Two Elements YAGI gain
is 3-5/8 collinear. Such collinear has height near 5 meters. So,
what is easy to install at the balcony?
Two Elements YAGI loses 1-dB in gain compare to Three Elements YAGI.
However, Two Elements YAGI has boom twice less in length compare
to Three Elements YAGI. That is why I have chosen the Two Elements
And the last. Why I did configuration “Vibrator- Reflector?”
Because the combination has good forward gain thought not good
suppression of back lobe. Combination “Vibrator- Director” has
good suppression of back lobe but bad forward gain. I need good
1 shows the design of the Two Elements YAGI. Antenna
elements are made from aluminum tube in 10-mm diameter. Traverse
made of from L- Shape aluminum with sizes 20x20 millimeters. Antenna
has input impedance 50-Ohms, so, coaxial cable straight away turns
on to the antenna.
Several ferrite rings (that do an RF-Choke) are installed
on the coaxial cable near feeding terminal.
insulated from the traverse. Plastic pieces are installed between
antenna elements and traverse. The pieces made from a water pipe
with OD 20-millimeters (3/4”). Length of 70 millimeters is cut
(longitudinal section) on to halves. One piece is going for vibrator
another one to reflector. At the vibrator’s piece drill a hole
in the centre.