A homemade antenna for radio operation in FM mode is a good opportunity to improve the quality of signal reception in the range of 88-108 MHz. To begin with, we will look at how to replace a standard antenna with a device of another type - a dipole.
Independent manufacture of an antenna for receiving radio.
Many types of receivers have a connector for connecting a simple external antenna - usually a built-in or telescopic rod. Make a good FM-antenna with your own hands, you can even for little money. For this, one visit to the nearest household goods store is sufficient.
Necessary funds
A set of tools and parts will be as follows:
- Ceramic insulators, as well as connecting elements for them. Do not allow the circuit of the antenna wire to nearby structures. Such funds can be purchased on the market of radio products or found in old buildings.
- Thin steel cable for connecting insulators.
- Roller blocks. We use them to install an external T-shaped antenna for the radio in a tensioned state.
- Plug to connect the antenna.
- Device for protection against thunderstorms. A two-position switch should serve exactly this purpose. A good outdoor antenna can quickly disconnect from the equipment and be grounded during a thunderstorm.
- A piece of copper wire. Diameter - 1.5-2 mm. You can also use steel wire wrapped in zinc. Copper will be more convenient to make installation work.
Types of antennas
FM antennas can be divided into three separate types:
- traveling surface wave;
- linear;
- aperture
An aperture is called antenna rotation. Wave channels - it is rather a special case of designs with a traveling wave. The directors in their modules are arranged so that they have vertical polarization. It is on the wave channel that television is caught. Antenna FM allows you to take into account the features of the future location.
Installation of the radio signal catcher
The installation of an outdoor antenna of a horizontal type begins with the selection of supporting structures. On them you subsequently fix the insulators with your hands. One of the supports must be installed on the roof of the house. It needs to be strengthened with wire stretch marks. A tree of suitable height can be used as a second pillar. Insulators can be installed on construction sites with steel cables.
With insulators you have to fix the outer part of the FM antenna with your own hands. It does not need to be subjected to great tension. The wire is compressed if the air temperature is low enough and can lose integrity at low temperature. Roller blocks will eliminate unnecessary vibrations. To use them, place a small cargo at the second end of the wire. It will be connected to the FM-antenna, if you throw it through an insulator and a block.
The receiving part of the antenna should consist of one piece of homogeneous material. If you do not have a homogeneous wire, it is better to make an FM-antenna of separate identical elements. They need to be cleaned and soldered with tin. The equipment for vertical descent of the antenna does not present serious difficulties. Please note that the wire must not be connected to foreign elements. Do-it-yourself need to fasten the antenna wire on a special stand. This will not allow him to be in the wrong position in windy weather.
If the place to install the FM-antenna with your own hands is limited, you need to apply a different design. This is a few pieces of wire, which have the appearance of a “broom”. At their lower ends they will be securely connected by cable. The ends of the wires can be poured tightly with molten tin. You need to cover the sealing area with reliable insulation in the form of bitumen or similar material.
A homemade indoor antenna would be the best option to replace an external trap. Insulators must be fixed indoors. Their location closer to the ceiling will give an advantage in the quality of signal reception. The wire should be stretched horizontally or coiled up.
Resonant loop antenna example
Resonant loop antennas are successfully used by mechanics to receive shortwave signals. To conduct directional reception of a signal, simply rotate the antenna in any possible plane. The magnetic component of the radio wave field allows you to receive a signal much cleaner.
How to make a frame structure?
Aluminum hoop with a diameter of 77 cm and an inner diameter of 1.7 cm can be found in almost any sports store. Plumbing pipes from the combined design of metal and plastic are well processed. For radio, a copper tube of a slightly smaller (16 mm) diameter is also a good fit.
Antenna Rakhmattulaeva
The design of the radio antenna is quite simple.
- The central core, braid and a short length of coaxial cable should be soldered to the contacts of a capacitor of variable capacity.
- The other end, the central core and the braid must be soldered to the aluminum hoop. You can also use car clamps that need to be carefully cleaned, with a diameter of 16-26 mm. The place of contact must also be carefully cleaned.
- The ratio of the length of the circumference of the frame to the length of the circumference of the bond loop should be equal to 1: 5.
- From the end of the coaxial cable, as well as from the central core, you need to remove the external insulation for a length of 1 cm.
- From the middle of the cable for the FM antenna, you need to measure half a centimeter in both directions and remove the outer insulation. After that, the cable braid is required to be removed. This will lead to its rupture.
- Check the range of the transceiver so that the frame has a resonance of 5 to 22 MHz. With other capacitor capacities, you can change the parameters of the receiving-transmitting device.
- If you are more interested in ranges with low frequency - it is better to use a frame with a diameter larger - 1 or 1.5 meters. If the high-frequency - 0.7 meters.
This solution is a simple option to get a resonant antenna capable of operating in many bands. Its radiation pattern will be figure 8. Aluminum and copper antennas work approximately equally.
findings
We have brought to your attention the popular types of antennas for radio, which can be made by hand. Most of these solutions are simple enough to make a house, and the simplicity of their settings will allow you to easily cope with the most difficult problems.
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