When the radio does not catch well in the car, many try to solve the problem in the same way - they buy the first active antenna that comes across. But the result does not always live up to expectations. The signal either does not improve at all, or not at all frequencies, or even nasty interference is added to the “silence” on the air. In fact, it can be bad to catch the radio in the car for many reasons. In this article, 10 of these are considered. In parallel, the principles of searching for a particular cause, as well as ways to improve the quality of radio reception, are described.

The radio in the car does not work at all

Before attempting to amplify the signal or remove interference, make sure that your car stereo is capable of picking up and playing analog radio broadcasts. If this is not the case, then no active antennas will help solve the problem. You are just wasting your money. But some branded antennas are comparable in cost to simple radio tape recorders.

There are several ways to make sure that the radio receiving part of the car radio is working:

  1. At some frequencies, some bad signal is picked up.
  2. In the city or its environs there is a more or less confident reception on a couple of channels.
  3. Radio catches well in another car.
  4. You rushed to buy a cheap active antenna, and the radio began to play, but not in the way you would like.
  5. When the transmitter is connected, the radio reliably reproduces the transmitted signal.

The last way is the most correct. A transmitter is a device that reads audio files from a flash drive (flash drive) and broadcasts them on the air at a certain frequency. You can buy it at any auto store for a couple of dollars. In the early 2000s - an unusually popular device. So, if the radio receiver confidently receives and reproduces the signal from the transmitter, the radio in your car is working.


After making sure that the receiver built into the car radio is working, start looking for the reason why the radio does not catch well.

Too bad radio signal

Perhaps the most common reason why the radio in the car catches badly. A weak signal is a problem that car owners everywhere face far outside the city. The thing is that the broadcast towers are too far away, and the analog signal is far from ubiquitous. It does not reach your radio for several reasons. This is the spherical shape of the Earth, and various obstacles - tall buildings, landscape, plantings, and so on.

Bad radio signal
Bad radio signal

However, a bad signal does not mean the complete absence of such in the reception area. Despite numerous obstacles, radio waves can still travel very far. But with increasing distance and the number of obstacles passed, the signal weakens. Accordingly, if the radio does not catch well for this reason, the radio waves that are “around you” should simply be “caught” more carefully and, possibly, amplified.

How to make sure that the radio in the car catches badly precisely because of a weak signal? Very simple. Necessary check how the reception works somewhere closer to the broadcast tower. As a rule, they are located in cities and other large settlements. If in such areas your radio starts to work normally, and where you live, it hisses and does not catch, then the reason is a weak signal.

This problem is solved in several ways. Again, active antennas, which everyone hopes for, are far from a panacea here. It is quite possible that for a confident reception of a weak radio signal in your case, a functional passive mast and interference elimination will be enough. This is discussed a little below.

In general, if the signal is clearly bad, then a high-quality active antenna will help to amplify it and reproduce it without interference. Just remember that solid and cheap are two parameters that cannot intersect in any way in the same model. In practice, it has been proven that Chinese "active" boxes at an attractive price do not enhance anything. And sometimes they generate such interference that the desire to listen to the radio in the car disappears completely and for a long time.

Curious motorists have repeatedly taken apart cheap "active" models and found nothing inside that should amplify the signal. At best, such a device somehow worked due to the presence of a long wire and small "horns". That is, the amplification effect was manifested exclusively on the principle of an ordinary passive mast. Roughly speaking, a free piece of wire works just as well.

Radio signal too strong

Much less often, but because of the strong signal, the radio can also catch badly. This problem is sometimes faced by owners of budget car radios living in big cities. The fact is that for confident reception in such conditions there is the most important thing - a good signal. However, due to the fact that there can be several radio waves with the same or similar frequency, they overlap each other, and chaos is reproduced in the speakers.

A good quality car radio is able to "filter" everything superfluous in such conditions. That is, as a result, only the strongest signal available is reproduced, without interference, overlays and distortion. Cheap devices do this “cannot” because of poor circuitry. Unfortunately, it is almost impossible to solve this problem. Although partial elimination of interference is often obtained by using filters along the power line and transmitting a radio signal over a passive antenna cable.

Problems with external passive antenna

There are several problems. The very first and obvious one is that the radio catches badly when the antenna is completely absent. Please note that its role is not necessarily a long mast mounted on the roof or trunk of a car. Very often this function in the car is performed by the rear window defroster. Therefore, before you buy and fence a huge pin on the roof, make sure that your car does not provide for receiving a radio signal through the heater grid.

External passive antenna
External passive antenna

How to check it? To do this, it is necessary to inspect the places where the glass heater is connected to the power supply. If more than two wires fit the grid, then the third one should go to the radio. Often, somewhere in these places you can find an amplifier. If only two wires are suitable for the glass heater, then your car is not designed to pick up a radio signal in this way.

Another issue with external passive masts is the material they are made from. Very often in auto shops come across the so-called dummies. The mast can be infinitely long and high, but it will not catch anything, as it is made of anything but metal. In conclusion, it should be said that antennas that are supposedly intended for installation in a car are complete rubbish. Under no circumstances should you buy these. Even if the description convincingly talks about effectiveness. Only active amplifiers can work effectively in the cabin. And even then, not everyone.

Additionally, it makes sense to purchase or make your own noise suppression filter if the radio catches, but is bad. In its simplest version, it is a ceramic or film capacitor with a capacity of approximately 100 nano-farads. Maybe more capacious. You will surely find such a capacitor in any unnecessary electronics. For example, in an old broken radio and so on. To turn the found capacitor into an anti-interference filter, it must be soldered into the gap of the passive antenna cable.

Film and ceramic capacitors
Film and ceramic capacitors


Electrolytic Capacitors
Electrolytic Capacitors

Please note that only ceramic or film capacitors without polarity are suitable for making a primitive noise filter. Accordingly, barrel-shaped electrolytic capacitors cannot be used in this case. Harm, of course, from them will not. But it won't make any sense either.

Passive Antenna Cable Problems

Any car radio with a radio has a connector for connecting an antenna. It is the same for an active antenna as for a passive one. The cable by which the passive mast or mesh is connected to the radio must meet at least two conditions. First, it must be intact. You can verify this by testing with a multimeter. Second, the cable must be shielded. An ordinary wire will not work here, since it will additionally catch all conceivable and inconceivable interference around.

Cable for connecting a radio antenna in a car
Cable for connecting a radio antenna in a car

If you didn’t find a standard cable in your car, you can buy it and stretch it carefully with your own hands. Although, probably, buying a ready-made active antenna seems to be a much simpler solution. She already has a cable with a plug. And the device itself is located in the passenger compartment, which means that you won’t have to pull the cable outside or through the weight of the passenger compartment into the luggage compartment.

How to make sure that the radio in the car does not catch well due to the cable of the passive mast? To do this, you need to find a place where the radio receives at least some kind of radio signal. Next, you just need to remove the cable from the connector. If the reception has not changed in any way, then the cable is either damaged somewhere, or not connected to the antenna at all. Reception deterioration indicates that everything is in order with the cable.

Freelance appliances in the cigarette lighter socket

Quite often, radio interference in a car is generated by freelance electrical appliances. They interfere especially strongly if the radio tape recorder is unpretentious, and there are no appropriate filters in it. There is only one way to make sure that freelance devices are not the cause of a poorly playing radio. It is necessary to temporarily disable (if any):

  • video recorder;
  • radar detector;
  • security alarm;
  • phone charger;
  • freelance voltmeter;
  • fridge;
  • inverter and so on.
Lots of appliances in the cigarette lighter socket
Lots of appliances in the cigarette lighter socket

If after that the quality of the radio in the car has improved, then the problem is obvious. Naturally, no one wants to get rid of, for example, a DVR just to listen to radio broadcasts in a car. To get rid of the interference created by freelance devices, it is enough to either power them through normal chargers, or use filters along the power line of the radio.

Poor-quality car radio circuitry

This has already been said a little above. If the radio tape recorder was initially poorly made, then, most likely, even super-expensive active amplifiers will not help to get the radio to catch the way it should. How to check? One way is to disassemble the car radio. Find microcircuits marked SAA or TEA on the board, and carefully follow the tracks that depart from them. If on the way you find empty places provided for some radio components, then the manufacturer saved money, and the radio should not play normally.

Car radio board
Car radio board

Craftsmen in such cases sometimes modify what the manufacturer cheated on. However, all this requires knowledge in the field of radio electronics, and is far from always worth the lost time. Nevertheless, as an option to improve radio reception and get rid of interference, it has the right to exist.

Indirect radio interference

These include various parasitic waves, which in our time literally permeate the entire ether. If there are no filters in the radio that can filter out this kind of interference, the radio catches badly, hisses, crackles, clicks and does anything, just does not play. You can make sure that the signal catches badly due to indirect radio interference if you get rid of them for a while.

Radio power filter
Radio power filter

First of all, check the operation of the radio in the car by turning off or removing the mobile phone, navigator and other external devices from the passenger compartment. In addition, quite often they try to tune the radio near residential buildings. And they have microwave ovens, TVs, computers, Wi - Fi routers and other electronics, one way or another radiating waves into the air. Of course, a good radio can filter all this garbage. But is it like that for you? Power lines can also affect the quality of radio reception. Accordingly, if you move away from all the listed benefits of civilization, you can be sure whether they or not they worsen the operation of the radio in the car.


Interference on the power line of the radio

Even if there are no devices in the car, such as a DVR or mobile phone charger, radio interference can be associated with the direct power supply of the radio. There is a lot more in the car that generates spurious signals to the on-board network. This is the ignition system, and the generator, and standard electronics.

To get rid of such interference, it is best to buy a special filter, which is installed in the power gap of the car radio. They are inexpensive, and the effect, as they say, on the face. You can also make a fairly effective food filter with your own hands. Just from one radio component. It's called inductance. These radio components can be found in any broken radio, TVs and other devices. The inductance is soldered into the gap of the positive power wire of the radio on either side (it has no polarity). And the radio part looks like this.

Poor quality active antenna

Cheap active antenna
Cheap active antenna

There is nothing to explain in detail here. The market is full of antennas that say they are active. Although in fact they are at best an interference suppression filter, or at worst just a piece of wire with horns. As practice shows, really high-quality active antennas start at a price tag of $ 30 and above. Although they help to improve radio reception in the car, not always. This happens if the reason is not in a weak signal, but in something else.

Brief summary

Good active antenna
Good active antenna

In conclusion, we will compile a summary table with all the common reasons why the radio does not pick up well, and how to eliminate them.


Why is the radio bad?

What to do

Radio doesn't work at all

Check the radio for operation in the city, using a transmitter or in another car.

Too weak signal

Install and connect the passive antenna with the correct cable. If it catches bad anyway, buy a good active one.

Too strong signal

If the radio signals overlap or there is interference, install a noise filter in the antenna cable break. As a rule, there are no such problems with high-quality radio tape recorders.

Dead passive antenna

It may be missing, disconnected, connected with the wrong or damaged cable.

Damaged cable

Connect the antenna with shielded cable. Verify that the cable is working with a dial tone.

Freelance instruments

Devices such as a DVR, a radar detector, a mobile phone charger create interference. You can protect yourself from them either by filters or by eliminating the source of interference.

Poor quality radio

Not always an inexpensive radio tape recorder is bad in terms of radio reception. You can check this by disassembling and studying the binding of radio microcircuits.

Indirect radio interference

Mobile communications, Wi - Fi, microwave ovens, industrial equipment, high-voltage power lines and more - notably clog the radio. If the radio does not catch well because of this, then external noise suppression filters or buying a high-quality radio can help.

Power Line Interference

They are solved by installing an interference suppression filter in the power circuit of the radio. In good radio tape recorders, such filters are already inside.

Bad active antenna

As a rule, cheap active antennas do not solve the problem in any way if the radio in the car does not pick up well. Better not to buy them at all.


As a result, we see that the radio does not catch well in the car for various reasons. Most often this is a weak signal. However, there are often those cases when the reason lies in interference. Therefore, before spending money on an expensive radio or active antenna, work out all the possible causes of poor radio reception. Perhaps the problem can be fixed at all for free.

VIDEO: poorly catches radio in the car