1. Manufacturing method of simple antenna: firstly, nail a hole on the outer side of the opening of the pop-top cans, pass through a screw, and fix two pop-top cans on an insulating strip (this insulating strip can be replaced by a plastic ruler used by students). Then, take a section of 300 Ω feeder (the length is about two meters as required) and fix it on two screws on the insulating strip, and the other end is connected with a matching device (75 Ω). The distance between two buyers of Elayao is 60-80mm. Finally, find a beautiful wine bottle as the base, make a hole in the bottle cap and fix the antenna with insulating strips.
Debugging method:
① the position of the movable antenna
② The antenna can be rotated during debugging.
③ The included angle of the antenna can be adjusted.
Second, the manufacturing method of the second simple antenna: 6 cans, 1 thin copper tube (or 8 steel wires) with a length of 90cm, and 5 insulating strips.
(1) connect and fix five insulation boards with cap screws to make a bracket as shown in the figure (the long side of the frame is 42cm, the wide side is 12cm, and the hypotenuse is 20cm).
② Fix three groups of tanks symmetrically and parallelly on the bracket with cap screws. The spacing between AB, CD and EF (referring to cans) is10cm; The spacing between AC, CE, BD and DF is 20 cm. From G and H, the midpoint of CE and DF is 10 cm, respectively. Bend the thin copper tube (or copper wire) into a ring (25 cm in diameter) and fix it on G and H with cap screws, so that the copper wire ring is perpendicular to the bracket.
③ Connect both ends of the flat feeder to the screw post with cover of the CD pop-top can and tighten it with nuts. In addition, two short wires (ordinary power cord is enough) are used to fix the well connected between CG and DH tightly, that is, the two screw posts of the middle group of cans are connected with the two ends of the copper wire ring.
④ Place a small wooden stick at the center "O" below the frame, fix it firmly with wooden screws, and insert Xiao Mu into the bamboo pole and tighten it. Putting bamboo poles on the roof or balcony and aiming one end of AB group cans at the main TV tower can get satisfactory results.
This omni-channel pop-top TV antenna is especially suitable for remote mountainous areas.
Third, a TV antenna with good reception performance can be made by assembling aluminum cans slightly, as shown in the figure.
Two aluminum tubes with a diameter of 10mm and a length of 85mm are mainly used. The included angle between the two main pipes is 90, the A and B ends are fixed on the insulation board D with screws, and the insulation pipe L is used to strengthen the fixation. Six branch pipes with a length of 14cm are welded and fixed on each main pipe, and the included angle between the branch pipes and the main pipe is 45. Use a 300 Ω feeder at the A and B terminals, and then connect to the TV through a 300/75 Ω impedance conversion plug.
The assembly method of the can is: punch a hole in the upper and lower covers of the can, then put it on the branch pipe and fix it with a screwdriver.
When in use, place the antenna horizontally at the height of the roof or TV station without obstacles, then adjust the position (orientation) of the antenna while watching TV, and adjust it to the best position and fix it. The antenna has good reception effect on 1-38 channel.
Fourthly, the TV antenna made of 12 can has a better effect of receiving TV signals than other antennas made by ourselves.
Aluminum cans are easy to get for cans of various drinks and are the main materials for antennas. Generally, a T-shaped wooden bracket is made first, and six cans on each side are fixed on the beam. Drill a hole at the center of the circle at both ends of the can, the hole is 1 ~ 2 mm, just enough to go in and peel off the copper core wire. Wires with thicker cores should be selected. Fasten the jar tightly, fix the wire core on the nail, and make it according to the attached drawings. In order to be firm, the cans are tightly tied to the beam with metal wires, and the copper wires on the two nails in the middle lead to the TV.