One of the major mood killers is a situation where FM radio doesn’t work but AM does & AM radio doesn’t work but FM does.
At other times, your FM and AM radio work just as fine, but your device finds it hard picking up some signals.
It is particularly true if you are about to tune in to your favorite radio program.
But what could be the cause? Why would your radio decide which band to connect to and which to shy away from?
To understand why this happens, you need to know what triggers and causes this.
And thankfully, we wrote this content to address just that. So, sit back, grab a can of your favorite soft drink; read and enjoy!
FM & AM Radio How Do They Work In Home & Car?
FM and AM radio work by receiving and transmitting signals in the form of electromagnetic waves.
In a sense, they are electromagnetic waves that travel very swiftly in a back and forth manner.
In the radio, there’s a transmitter that radiates the signals outward through an antenna.
This signal is now picked up by a receiver which functions as a translator that translates the signal to the sound you now hear via the radio.
In Amplitude Modulation (AM) radios, the amplitude (strength) of the signal is modulated (changed) to help the radio produce sounds.
On the other hand, Frequency Modulation (FM) radios have their signal’s frequency (speed) changed instead of the amplitude.
When tuning in to your radio, the numbers you’d find on the dial panel indicated mega or kiloHertz of the broadcasting signal.
Radio signals utilize a certain frequency, or how the speed with which the signals in the electromagnetic field travel in an up-and-down motion.
Hertz, named after a popular scientist, is the unit for measuring the movement of these waves (in cycles/second).
The frequency of the waves in AM radios is expressed in kiloHertz, and its counterpart, FM radio, is conveyed in megaHertz.
The radio station that is broadcasting the signals may affect the range of these electromagnetic signals.
Also, the station can affect the overall distance of these electromagnetic waves.
As of the time of this writing, the strongest AM signal power permitted for operation in the US is fifty thousand watts.
FM Radio Doesn’t Work But AM Does
Sometimes, your radio may not have a hard time picking AM signals but does for FM signals. Below are some of the root causes and their suggested solutions.
Problem with the FM tuner section
Your radio may not pick FM signals if it has an issue with its FM tuner section.
A component in the local oscillator or the front end of the FM tuner section may have failed.
If you are a DIYer, you may want to open up the radio using a matching screwdriver.
If you feel the problem is way above what you can handle, then it makes sense to check out your neighborhood’s radio repairer to help with the problem.
Misaligned tuner
Sometimes the reason why your radio is not picking up any FM signals is that the tuner is misaligned.
In that case, you need the services of a technician to help you fix this problem.
The technician must be conversant with the use of dedicated electronic testing tools if he must offer any tangible help.
If your radio is a vintage tube one, then a bad tube problem with the bad tube may be what is making it not bring up any FM station.
Disconnected FM antenna
While this sounds already obvious, it is not uncommon to find some folks making the mistake of not making sure that their FM antenna is connected to the radio. Result? Your radio may not pick certain FM signals.
Connect your FM antenna to fix this. If the problem persists, then check out your technician.
AM Radio Doesn’t Work But FM Does
Problem with the antenna cable
In some radio setups, an adapter connects directly to the radio instead of a normal specialized CB antenna.
Normally, this should not cause any problem, but it is also possible that it does.
To check if this is the possible reason why your radio is not connecting to an FM station, disconnect the CB antenna.
If your radio picks FM signals after this disconnection, then the CB antenna is most likely interfering with the radio signals.
Metalized window films on cars
Window films built with metals may create a reflective appearance.
Aside from their visible light reflection ability, these metals also can interfere with the reception of signals in the radio of certain cars.
In some cars, a tiny antenna wire runs to the rear mirror from the windscreen.
If your car is like this, do not use a window film strip built with metals.
There is no need for any alarm if your car utilizes a solid antenna on the roof or hood of your car.
Class D amplifiers
The reason why your radio isn’t picking any FM signal could be because it is using a Class D amplifier.
Disconnect the amplifier power source to check if this fixes it. If your AM signal reception becomes better, then your amplifier is the problem.
How To Improve FM/AM Reception
Even if you are residing in a good location, several radios out there do not properly pick weak signals.
Perhaps, this may be your current dilemma. The points below will show you how you can improve the receptivity of your radio. So, how exactly do you improve your FM/Am reception?
Reduce Interference
To reduce interference;
Change to FM mono
It is true that many radios out there do not come with this feature, you may be lucky to still see some radios possessing it if only you can search well enough.
When present, it normally appears in an FM or switch mode button.
The normal way of playing a radio broadcast via audio is by using FM stereo.
Most contemporary radios use it. Search for a switch on the radio’s side that includes FM stereo/FM.
When converting a signal from an FM to stereo, it degrades the ratio of the noise to signal.
What this means is that when heard on the stereo, the signal will be worse. To many radios out there, this is a tangible difference.
It is possible that you once noticed that the radio in your car changed to mono.
This is an auto function that the manufacturer put in place to help you enjoy the best signal.
Turn off electronics nearby
Having tons of electronic gadgets in your house can interfere with your radio signal.
Turn it away from these gadgets, or if you will, kindly turn the gadget off when you on your radio.
Interference effects may be severe or mild contingent on the strength of your radio and your distance from them.
Some examples include screens/monitors, light dimmer switches, DVD players, VCRs, CD players, fluorescent bulbs, halogen, microwaves, cable boxes, and of course, computers.
Alter your location
Your radio signal’s nature is indicative of the existence of a sweet spot in the room where the radio is kept.
You may want to change the location of the radio occasionally to see if you get some signals.
If that room is completely bereft of signals, you may want to try out other rooms. The receptivity of radios to signals is very important.
Concrete and steel have obvious effects on your radio’s receptivity.
You’d get the best results if the position of your radio is somewhat elevated and nearer to the transmitter.
Also, try positioning an outdoor antenna on the roof of your house to help you get signals.
Does your radio pick up the signal?
Unlike what is obtainable with portable radios, the radio in your car comes in handy when you are on a high speed.
This is especially true when touring past different roads and terrains.
If your radio’s manufacturer didn’t create a good product, there’d be a lot of interference on the road.
Also, they should be sufficiently powerful so that they can withstand interference from your engine.
Bettering Your Antenna
Utilize a dipole antenna
Some radios feature dipole antennae. It has a T-shape and comes with dual branches that you can use ford signal detection.
Ensure that the position of the antenna is on the window. Make sure you spread out the antenna branches as far apart as possible.
While the result may not likely be remarkable or extreme, it still offers you a tangible step up.
Experiment with outdoor antennas
While outdoor antennas remain better than their indoor counterparts, the fact remains that they are quite expensive.
And the signal can get pretty bad if you don’t adjust the antenna properly.
When you opt for outdoor antennas, ensure they go for those you can mount in the attic or on the roof.
Most antennas that are roof-mounted will offer you receptivity similar to those in car radio – sometimes, even better.
Try reconverting a TV antenna to the one you can use in your radio using an FM splitter. This is the go-to option if you don’t plan on buying another radio antenna.
You may also want to opt for an omnidirectional antenna. It is so-called because of its ability to receive signals from every direction.
If you’d like to get signals from certain directions, you can use an antenna rotator.
Because of the effectiveness of these antennas, most radio stations utilize them for measuring the strength of signals in their radio stations.
Frequently Asked Questions
How do I decrease interference in my AM radio?
The simplest way you can lessen the interference of signals is to utilize smaller radios and tune in to an AM station plagued by noise.
After that, disconnect your radio from the main power source or start turning off your radio’s breakers one by one.
If a large chunk of the noise stops abruptly, then the source of the noise is most likely from something in your house.
Does aluminum foil augment radio receptivity?
Generally, it won’t help anything and may hurt your reception. It actually depends on some criteria though, mostly the antenna of the radio itself and the desired frequency which you are trying to receive.
Putting foil on the end of the antenna will in effect make the antenna longer.
Why does my radio antenna lose its signals at night?
A decrease in climatic temperature as day turns into darkness, and weather changes can lead to signal loss.
People often refer to this as falling off from the digital cliff.
Which is better, FM or AM?
AM is far more prone to interference than FM. Also, the signals from FM are affected by physical obstacles.
In AM radios, the bandwidth of the modulating signal is fifteen kiloHertz and the bandwidth of an amplitude-modulated signal is thirty kiloHertz.
Which travels further, FM or AM?
The radio waves characteristic of FM signals travel skyward and horizontally.
But, because of the greater frequency of the transporter wave, there’d not be any reflection of the wave that travels skyward.
They travel through the air and plunge deep into space. You can get AM signals at higher distances than you can get for FM signals.
AM signals are more affected by static than it affects an FM signal. Static is due to the presence of electrical energy in the atmosphere.
Also, FM signals result in a more correct reproduction of sound than what is obtainable for AM signals.
Conclusion
No doubt, life happens and it is often when we least expect. One of such happenings is denying us from listening to our favorite radio stations.
The inability of radios to either pick AM or FM signals is due to a certain cause or series of causes.
And the way you approach them is entirely dependent on what is wrong. Like we advised earlier, you can check out your local radio technician if you feel the problem is way beyond you.
But if you are a tech-savvy DIY-er, then you can take the bold step and do it by yourself by following the suggestions we gave earlier. When you do, you’d enjoy wonderful results.