How to properly amplify the radio signal in the car stereo

Even though car stereos have perfected their technical solutions, they can still disappoint their owners when it comes to receiving radio or television signals in remote areas. The sound becomes distorted, filled with interference, or might even disappear completely. To address this issue, an antenna amplifier for car stereos can be used. By properly connecting this device, it can help eliminate these problems. There are numerous models available on the market, or one can be crafted from scratch.

When you should buy an amplifier

• The signal experiences a brief disturbance and the volume drops.
• When the car is far out of town, there is a characteristic hissing noise, commonly known as white noise.
• The signal freezes and eventually disappears completely.
• The number of received stations may decrease, or some stations may no longer have a signal in the list of previously found stations.
• No radio signal is received at all.
• Analog TV channels are received with low quality, broken sweep and synchronization, and noise in the image.
• The picture of digital television freezes, disappears, and the stereo displays the message "No signal," or the image is scattered with squares.

These indications indicate the need to enhance the radio signal in the car stereo by linking an external module. At present, there is a wide range of devices available in the market that address this issue. A classic car stereo can be connected to an FM amplifier of any model. However, certain devices are only compatible with modern multimedia stations that have specific connector features for utilizing an external antenna.

How to choose a gain module

When choosing an fm signal amplifier for a car stereo, the first factor to consider is the type of power supply it uses. Currently, there are two different types of devices available on the market.

1. Amplifiers with external power supply. These amplifiers have a separate branch wire that needs to be connected to the car’s onboard network.
2. Amplifiers with power through the antenna cable. These devices can only be connected to specific types of radios that have the capability of powering the amplifier through the antenna cable.

Connecting the antenna amplifier to the car stereo is a simple task, regardless of the technical solution. However, it is essential to purchase a device with the correct specifications. The following criteria should be considered when selecting the optimal model:

1. Determine the frequency bandwidth based on the type of stereo and the radio tuner installed. For older cassette models that receive short, medium, and FM waves, a wideband amplifier is necessary. Modern stereos only require a narrowband model that operates in the FM band.
2. Consider the type of antenna that will be connected. Conventional pin models can be paired with a standard amplifier. However, if a directional (also known as dipole) antenna is being used on the car, a more complex device is needed. This circuit solution includes a matching module.
3. It is advisable to set the gain between 10 and 30 dB. Presently, you have the option to purchase models that come with a high level indicator. Nevertheless, it is not advisable to do so in the majority of instances.

The process of selecting the optimal gain deserves a detailed explanation. It is not only determined by the desired reception range. The maximum power of the car’s stereo amplifier plays a crucial role in determining the final signal level at the device’s input. However, there is a technical limitation on how much it can be increased.

In cases where the installed antenna amplification module is too powerful and the car is in an area with strong reception, such as a bustling city, the car stereo will simply stop picking up radio signals. This is due to the protective system that kicks in. The amplification device, producing an excessively strong signal, will push it beyond the technical limit. As a result, to safeguard the primary reception circuits, the antenna input will be blocked, so to speak.

Here’s a handy tip for you! Based on our research, we’ve found that for an average boombox, if you’re looking to pick up FM radio signals within a 100 km radius from the city, you’ll just need an amplifier with a gain of 10-15 dB. However, if you spend most of your time outside the city, you might want to consider getting a model with a higher gain.

When using a car’s real image, it is advised to install an amplifier blocker to enable its movement within the city and to drive beyond its boundaries. This device is designed to disable the amplifier when necessary by creating a detour through the main cable channel of the antenna. It is possible to purchase an amplifier that automatically disconnects when the signal output reaches a specific threshold.

Recommended models

When selecting an amplifier for your car’s stereo system, it is crucial not to compromise on quality. It is not advisable to purchase devices of questionable reliability. Low-cost Chinese models tend to overheat and fail to demonstrate satisfactory performance. Moreover, inexpensive amplifiers often lack proper shielding and fail to deliver the advertised specifications. Fortunately, there exists a variety of models that have proven to be highly reliable and efficient in real-world applications.

Triad-304

This particular device is compatible with all types of car stereos. The amplifier has a wide range of frequencies, functioning in both the FM and short wave categories. It requires an external power supply and provides a 16 dB boost in gain. There is an automatic built-in bypass feature. It is advisable to disconnect the device in urban areas, as it may generate a signal that gets blocked by the car radio’s tuner. This can easily be achieved by interrupting the power supply. The recommended usage pattern for this device is primarily in city environments with occasional trips to rural areas.

The prices for the Triad-304 can be found on Yandex Market:

LADA

This amplifier provides great flexibility in its usage. It comes with two selectable gain options – 12 dB and 25 dB. You can easily check which mode the amplifier is operating in with the built-in indicator. Moreover, there is a shutdown function that can be activated by simply disconnecting the power cable. This particular model is ideal for both personal vehicles during outdoor excursions and for commercial transportation purposes.

BARF-3

The cost of this amplifier is quite notable. Nonetheless, the consumer receives dependable shielding for their investment, enabling them to position the device directly beside the antenna input of their car’s stereo system. The amplifier necessitates a separate power input and delivers a gain of 23 to 25 dB. It is highly recommended for installation in commercial vehicles and high-end automobiles.

Is it possible to make an amplifier with your own hands

Making your own amplifier can be done using one of the basic circuits that are widely available on the internet. However, if you prefer not to customize the solution to your specific needs and want to avoid fine-tuning, it is recommended to go for a ready-to-assemble kit. Nowadays, you can easily find and purchase these kits, commonly referred to as master kits.

One popular option is the NK147 model which has a relatively low gain and is ideal for trips to the cottage or country picnics. Another option is the NK138 master kit, which is a broadband amplifier with high gain suitable for universal use. This solution can be easily connected to any car stereo.

How to connect the amplifier

Anyone who has ever installed an active antenna either at home or in their car knows that the amplifier is typically positioned right next to the receiving circuit. The same principle applies when connecting modules in a car. The guidelines for this are straightforward.

1. If the antenna already has its own amplifier, it is best to avoid installing an additional external amplifier. Doing so could potentially distort the signal.
2. If the antenna’s amplifier is faulty or broken, you can connect an external amplifier in its place. However, make sure to remove the non-functional module.

If you opt for using a passive pin antenna, it is crucial to position the amplifier as close to the antenna’s pins as possible.

Pay attention! It is important for the user to consider one specific detail: most models are designed to be placed near the antenna input of the car radio. As a result, the output cable will need to be extended.

Mounting the amplifier near the car stereo is not advisable. Within the car, and specifically in its on-board network, there exist various electromagnetic and radio interferences. These interferences occur when the engine is running, during its start-up with sharp voltage spikes. If the amplifier is installed next to the stereo, it will significantly amplify their level and, consequently, result in severe buzzing.

Various methods can be used to organize the external power supply.

1. One option is to connect the power terminal of the car stereo. This is a versatile choice as the amplifier will only turn on and function when the car radio is in use.
2. Another option is to tap into the power source of other car systems. In this case, the amplifier will remain on at all times. While this option generates minimal heat and is generally safe, there is a risk of damage during a lightning storm.

To ensure the amplifier’s safety in the second method, it is recommended to implement galvanic isolation on the power supply cable. This will protect the amplifier from burning out in the event of nearby lightning strikes and interference. Connecting the amplifier to the car stereo is straightforward. Simply remove the cable from the antenna input and insert the corresponding branch of the external power supply.