The simplest zigzag antenna, known as the Kharchenko antenna, is very popular with home craftsmen. Most often it is used to receive television programs in the meter and decimeter wavelengths, and radio amateurs - to work in the VHF range (frequencies of 145 and 433 MHz).
It is necessary
- -hacksaw;
- -drill with a drill (d not more than 5 mm) for metal;
- -screwdriver;
- -knife for stripping the ends of the coaxial cable;
- -soldering iron;
- -8 strips of copper, aluminum or tin;
- -screws;
- -2 terminals made of tin;
- -coaxial cable;
- -5 wooden blocks;
- -metal rods;
- -screws.
Instructions
Step 1
For the manufacture of this simplest antenna, you need the following materials: 8 strips of copper, aluminum or galvanized sheet size L × B mm (L is the length of the strip, L = λ / 4, where λ is the average wavelength of the channel to which you want to tune, or corresponding to the middle of the TV band used in your area; determined by reference, see for example https://www.2x2business.ru/ant1.htm; B - width 10-40 mm); screws (rivets) for connecting strips to each other; 2 terminals made of sheet metal (10 × 10 mm, with a screw hole); coaxial cable with a characteristic impedance of 50 or 75 ohms; 4 wooden blocks of length (0, 17-0, 22) λ for fixing the antenna web on a wooden carrier, the wooden carrier itself (a wooden block, the dimensions of which depend on the antenna); metal rods (strips) with a length of 0.8 λ for the manufacture of a reflector; screws for fastening the antenna web (two for each of the 4 bar-rack) and metal strips of the reflector
Step 2
Cut 8 copper or aluminum strips to the required length. Drill holes at the ends of these strips with a diameter large enough to allow the screws that you will use for fastening to pass freely.
Step 3
Join two pairs of strips separately at an angle of about 90º, fastening them with screws. Place the assembled corners with loose ends to form a rhombus. Its loose tops are oriented up and down.
Step 4
Attach the resulting rhombus at its top vertex to one of the 4 posts using a screw. Spread the ends of the loose strips forming the lower apex of the rhombus so that the distance between the holes at these ends is 30-35 mm. Repeat steps 3, 4 to form and secure the second diamond, changing only the vertices for securing (lower) and the vertex, the ends of which are spread (upper).
Step 5
Put the two resulting diamond-shaped frames in the places of the holes of the loose strips, put the terminals made of tin on top and fix the whole structure in this form to the two remaining bar-racks using screws.
Step 6
Solder the coaxial cable to the tin terminals, one with the center conductor and the other with the braid. To prevent possible corrosion, the soldering point must be protected with a moisture-resistant varnish or glue. Attach 4 wooden posts with the resulting antenna strip to the support post. The cable can be secured to the lower antenna frame using insulating tape or plastic ties.
Step 7
To amplify the signal, a reflector consisting of parallel metal rods (strips) is attached to the carrier at a distance of (0, 17-0, 22) λ from the manufactured antenna. The width of such an amplifying screen is 0.8 λ, the distance between its rods is 0.08 λ. Instead of squares (rhombuses), triangles or circles are also used to make the antenna web.
