Everything You Need to Know about FM Broadcast Antenna

 

Antennas come in different shapes and sizes. Every antenna performs differently from another. Choosing the right kind of antenna is very important for gaining better performance. FM Broadcast Antennas help to receive high-quality FM broadcasts. They also help to receive strong indoor signals.

Antennas designed with bands between 88 MHz and 108 MHz are good for receiving the FM broadcast. They also give the most effective FM reception. In this blog, we will discuss everything related to FM broadcast antenna and its features, benefits, and how it works.

Basics of Dipole antenna  

Before we discuss the different features of a dipole antenna, it is necessary to learn its basics. Dipole Antennas contain two parts or poles. In a half-wave dipole, each leg is an electrical quarter wavelength long.

The length of the dipole is determined by the frequency operation. FM broadcast band extends from 87.5 MHz to 108 MHz. Coaxial cable is used for a balun in this type of antenna. The outer shield is attached to the earth and the antenna is balanced.

In a dipole antenna, the inner conductor of the coax is attached to one leg of the dipole and the outer conductor of the coax is connected to the antenna’s other leg.

FM interference

Problems of FM interference occur often when the distance between the transmitting and receiving antenna is increased. Tropospheric scatter causes parts of the FM transmissions to be retracted towards the earth at some distance within a normal line of sight.

This phenomenon occurs when a temperature inversion is located in the FM broadcast signal path. These signal refractions create FM reception. They can also disrupt the reception of FM broadcast transmission.

Obstructions to FM broadcast signals can range from small hills and buildings to mountains. The resultant effects could be partial absorption that reduces received signal strength. Multipath interference distorts the FM signals resulting in low-fidelity reception.

Steps to develop FM dipole antenna

It is very simple to design an FM dipole antenna. You will need some basic accessories to make this antenna such as:

·      Wrap to secure the center of the diploe and prevent the flex from opening out

·      Twin flex of old speaker

·      String or twine to secure the ends of the dipole to fixing points

·      Connectors connected to the coaxial cable

One of the major benefits of using mains flex is that it is used as a feeder for radio frequency signals. This wire is a close approximation to 75 ohms or a twin or open wire feeder. FM dipole antenna can be made with the help of a cheap speaker wire.

To design a VHF FM dipole antenna, the cable must have the two insulated wires split back away from one another and opened out. The next step is to secure the center to prevent the cable to open out. You can use a wrap that is available in most electronics components stockiest. You can use the length of the wire as the feeder for the antenna.

You must keep the length of the antenna at about 150 cm. Then you can knot the ends of the wire to attach it to some string. The knotting of the wire adds some inductance to the wire ends.

While installing the antenna in a roof space, keep it away from all the objects made of metal. The ends of the antenna are more sensitive to metal objects.

Common types of outdoor FM broadcast antennas

Now, we will discuss the common types of FM broadcast antennas in this section.

1. Crossed dipole or Turnstile

This Circular Polarization Antenna provides an omnidirectional receive pattern. It has low gain in all the planes.

2. Unidirectional dipole 

The next type of outdoor FM Broadcast Antenna is a unidirectional dipole. It is a large dipole with two elements and more gain than the common indoor twin lead dipole. This dipole antenna emits the signals in one direction.

3. Multi-element array

This is a kind of unidirectional antenna that can receive distant stations because of high gain. This gain is directional and needs an antenna to be rotated.

Types of Indoor FM antennas

Many urban and near-suburban areas cannot install an outdoor antenna. In these areas, an indoor FM antenna can be installed.  Let us have a look at the kinds of Indoor FM antennas:

·      Amplified indoor antenna

Amplified antenna designs have inherent tradeoffs in signal-to-noise and other negative RF attributes.

·      Unamplified indoor antenna

The unamplified indoor antenna has two basic antenna configurations.

·      ½ wave vertical

This vertical antenna has a high gain for an indoor antenna. It provides high-quality FM reception in urban areas.

·      Bidirectional dipole

These Directional Antennas are commonly used indoor FM antennas. Single, dipole design and ½ waves exist as an industry gain reference for most FM broadcast band antennas. It gives signals from all directions.

Benefits of using FM broadcast antenna

We discussed the different types of Horizontally Polarized Antennas. Now, let us have a look at the benefits of Omni directional Antennas.

Ø FM broadcast antenna is very easy to install and set up in urban areas and stations.

Ø These Circular polarized Antennas never rust or get damaged due to sun rays, winds, water, or snow. They work for a long time and give better performance than normal antennas.

Ø Vertically Polarized Antennas give high-quality FM broadcasts.

Ø It is easy to use these antennas without any professional guidance.

Ø Yagi Antenna give strong signals in all areas and directions.

Ø These antennas are cost-effective and give stronger signals than other types of antennas.

Ø One can design an FM broadcast antenna with the help of some basic materials.

Read more: Advantages and Disadvantages of Yagi Antenna

Where to find the best quality FM broadcast antenna?

Today, it is easy to get the best quality FM broadcast antennas from online sites. You can check the official site of FM Broadcast Antennas Manufacturer on Google engine. Some companies provide a long-term warranty on FM broadcast antennae to their regular customers.