Despite the perfection of technical solutions, car radios when receiving radio or television far from cities can disappoint their owner. The sound begins to fade, saturate with interference, completely disappear. The antenna amplifier for the car radio allows, to some extent, to eliminate this problem. It must be connected correctly. The device can be selected from numerous models on the market or do it yourself.
When to Buy an Amplifier
A radio signal amplifier for a car radio will be needed in cases where there are obvious manifestations of insecure reception. For example:
- the signal is briefly disturbed, the volume drops;
- there is a characteristic hiss, the so-called white noise, when the car is far outside the city;
- the signal freezes, disappears completely;
- the number of received stations becomes less, or there is no signal in the list of previously found ones for some positions;
- radio does not receive at all;
- analogue TV channels are received with poor quality, mis-scanning and synchronization, image noise;
- the picture of digital television freezes, disappears, the radio tape recorder displays the message “No signal” or the image crumbles into small squares.
All these signs mean that it is necessary to amplify the radio signal in the car radio by connecting an external module. Today, there are many devices on the market that solve this problem. FM amplifier for classic type car radio can be connected to any model. And some — only to modern multimedia stations that have certain connector characteristics for using an external antenna.
How to choose a gain module
The first criterion by which an fm signal amplifier for a car radio is selected is the type of its power supply. There are two types of devices on the market today.
- With external power. Such an amplifier has a tap, one wire for connecting to the vehicle’s on-board network.
- Powered by antenna cable. Such devices are connected only to a certain class of radio tape recorders. The latter must have the option of power supply over the antenna cable.
Regardless of the technical solution, connecting the antenna amplifier to the car radio is not difficult. However, the main thing is to buy a device with the right characteristics. The criteria for choosing the optimal model are as follows.
- frequency band is selected depending on the type of radio and the radio tuner installed in it. If this is an old cassette model that accepts short, medium and FM waves, a broadband amplifier will be required. For modern radio tape recorders, a narrow-band model is sufficient, operating only in the fm range.
- Type of connected antenna. For conventional pin models, a conventional amplifier is used. When using directional (they are also dipole) antennas on a car, a more complex device will be required. The circuit design includes a matching module.
- Gain should be between 10 and 30 dB. Today you can buy models with a large indicator. However, it is not recommended to do this in a huge number of cases.
The choice of the optimal gain should be discussed in more detail. It is determined not only by the desired reception range. The fact is that the maximum power of the amplifier of the car radio determines the final signal level at the input of the device. However, there is a technical limit to its increase.
If the installed antenna gain module is very powerful, and the car is in a good reception area, in a big city, the radio will simply stop receiving the radio. The protection system will work. The amplification device, forming an excessively strong signal, will bring its value beyond the technical limit. As a result, in order to protect the primary receiving circuits, roughly speaking, the antenna input will be blocked.
Advice! Practice shows that with the average parameters of the radio, and if you want to receive FM radio at a distance of up to 100 km from the city, an amplifier with a coefficient of 10-15 dB is enough. If the car is out of the city most of the time, you can purchase a model with a more impressive indicator.
When the real picture of the use of the car includes both its movement in the city, and travel far beyond its limits, it is recommended install booster blocker. This is a circuit that turns it off if necessary, bypassing the main cable channel of the antenna. You can buy an amplifier that turns itself off when a certain limit signal is reached at the output.
When choosing an amplifier for a car radio, you should not save. Buying devices of dubious quality is highly discouraged. Cheap Chinese models get hot, can’t show good uptime. Inexpensive ones are often poorly shielded, do not have real characteristics that correspond to the declared ones. There are a number of models that have shown good reliability and efficiency of use.
This device will fit for all car radios. The amplifier is broadband, operates in the FM and short wave bands. It has an external power supply and 16 dB gain. The built-in bypass operates automatically. The model is recommended to be turned off in the city, as it can generate a signal that is blocked by the tuner of the car radio. To do this, it is enough to interrupt the power supply. Recommended scheme for using the device: the city with trips to the country.
Prices on Triad-304 on Yandex Market:
This amplifier offers versatility of use. Him two switchable gains, 12 and 25 dB. The built-in indicator shows in what mode the device works. There is a shutdown function by interrupting the power cable. The model is suitable for both cars when traveling to the country, and for commercial vehicles.
This amplifier has a rather impressive price tag. However, for their money, the user receives reliable shielding, which allows you to install the model right next to the antenna input of the car radio. The device requires a separate power input, shows a gain of 23 to 25 dB. Installation on commercial vehicles and expensive cars is recommended.
Is it possible to make an amplifier with your own hands
You can make an amplifier with your own hands according to one of the basic schemes that the Internet is full of. However, if you don’t want to customize the solution to your own needs, and also don’t want to fine-tune it, it is recommended to use a kit ready for assembly. Today you can buy the so-called whale master.
The NK147 model is popular with a fairly low gain, for trips to the country or to a country picnic.. There is a master kit NK138. This is a broadband amplifier, with high gain, for universal use. This solution can be connected to any car radio.
How to connect an amplifier
Those who have ever installed an active antenna at home or in the country, know that its amplifier is located right next to the receiving circuit. Similarly, you need to connect the modules in the car. The rules here are simple.
- If the antenna has its own amplifier, it is not recommended to install an additional external amplifier. This can lead to signal distortion.
- If the antenna amplifier is broken, an external one is also connected in its place. A module that does not work must be removed.
In the case of using a passive whip antenna, you need to install the amplifier as close as possible to its outputs.
Important! Here, the user should take into account one detail: most models are designed to be placed near the antenna input of the car radio. Therefore, the output cable will need to be extended.
It is not recommended to mount the amplifier next to the car radio.. In the car as a whole and its on-board network in particular, there is a lot of electromagnetic and radio interference. They occur during engine operation, its start-up with sudden voltage surges. Installed next to the radio, the amplifier will significantly increase their level and, as a result, emit a lot of noise.
External power is organized in several ways.
- From the power terminal of the car radio. This is a universal solution. The amplifier will turn on and work only together with the car radio.
- From power rails of other automotive systems. The amplifier will always be on. It generates little heat and is harmless, but can be burned by lightning.
To protect the amplifier in the second switching option, it is worth doing galvanic isolation via power cable. Such a solution will not allow the model to burn out even with close lightning and interference. There are no problems with connecting the amplifier to the car radio. It is enough just to pull out the cable from the antenna input and insert the corresponding external tap into it.