VHF antenna type YAGI for 144 MHz
The author of this antenna - OH5YW. He published its design in 1976.
The antenna can contain from 3 to 7 elements and has a maximum gain of 8-10 dB. For the carrier to traverse any insulating material: wooden slats, Orgsteklo, the plastic tubing. The elements of the antenna is a thin wire segments (3-5 mm) of aluminum or bimetal.
All dimensions indicated in the figure.
The vibrator is consistent with coaxial cable using deltabase open symmetric matching lines from the same material as the antenna elements. The outputs of the line is securely connected with a continuous linear vibrator. The connection points are located symmetrically at a distance of approximately 11.5 cm in one and the other side relative to the center of the vibrator. The length of the line conductors 19 cm, they converge almost one-point - at a distance of 0.5 cm, and mounted on a small insulating pad. In this place to the input line connected to a standard half-wave balun and matching U-shaped knee from the same cable that is used to reduce. Delta matching device is preferably positioned perpendicular to the plane of the elements, but a valid location and in the same plane with the angle directed toward the Director.
The antenna is a quick design and with a traverse of the material at hand assembled to fit in a shopping bag.
Author: OH5ZZ; Publication: N. Bolshakov, rf.atnn.ru