There was a need to receive digital channels in car.
Primary requirements:
High gain.
Pie pattern.
Compactness.
Cheapness.
A circuit of a loop vibrator and a long Soviet past was found.
Broadcasting of the first multiplex in our region is carried out on the 33rd frequency channel.
If desired, you can count on any other channel. If you need to take two multiplexes, calculations are best done on the middle channel. For example: (45 + 33): 2 = 39.
We do the calculations:
33 channel -570 MHz.
300/570 = 0.52m.
0.52 / 2 = 0.26m.
L = 26 cm.
h = 2 cm.
D = 1-3 mm.
B is the size of the amplifier mount.
The calculations are carried out. We are preparing everything you need.
A flower pot of the simplest form. It is possible with a picture, if someone likes it. The author took a pot with a diameter of 100 mm. - 45 rubles in a hardware store.
Magnet from the old speaker.
Cork from a five liter bottle.
Antenna amplifier - 55 rubles.
Copper wire with a diameter of 2 mm.
A piece of cable with a plug from an old Soviet room antenna.
Several screws and screws with nuts.
We bend the loop vibrator from the wire according to the drawing. At the ends we make loops for screws with a diameter of just over 4 mm.
We fasten the amplifier with screws. The contact pads of the amplifier should be adjacent to the wire.
We fasten the magnet to the stand from the flower pot using the bottle cap as a washer.
We stick any dielectric to the edges of our vibrator. For example, insulating tape or tape.
We bend the vibrator, as shown in the photo by the diameter of the pot.
We make holes for the cable. We connect it to the amplifier. We close our design.
From below, you can stick a piece of flannel or velor fabric, so that the antenna does not scratch the roof of the car.
Solder the plug to the other end of the cable. We connect.
We are testing.
The reception is confident in medium-sized buildings and 10 km away from the repeater.