If you have multiple RC cars in close proximity, you may find that there may be some interference. I was wondering how it is possible to avoid this interference. Let me explain how you can do this.
How to Stop RC Car Interference? There are 3 ways, keep the cars apart, deliberately purchase cars on different frequencies or buy a band switchable RC car. Your choice will have different effects on the price. As you can imagine, the band switchable RC car will typically cost more.
Now you know how to avoid interference, let me explain in more details as well as how hobby-grade vehicles avoid interference in a more advanced way, how frequencies are allocated if licenses are needed for other frequencies and much more.
Methods to Stop RC Car Interference
When you are dealing with RC cars, especially the toy Grade level there is a good chance that you will run into interference. Especially if you were using multiple cars simultaneously.
For that reason, in this section, I’m going to explain how you can easily stop this RC interference.
The first thing that you need to do is to identify what frequency your car is currently set to. If you look on the bottom of the vehicle or around the packaging, you should clearly see what frequency it is set to.
On commercially available RC Toy grade vehicles, there are a few different ways that you can handle this.
Keeping your distance away from other vehicles
If you find that there is interference or potential conflict between frequencies. You can simply keep them away from each other.
I’m sure you are now thinking that’s all well and good but how do you know exactly how far to keep them apart to avoid this interference?
Usually, the interference will happen if they are within 75 to 100 feet away from each other. To avoid this, simply make sure that they are not in close proximity of each other.
In particular, way outside of this conflict range. For example, taking into consideration the distances I quoted above, don’t use the cars unless they are at least 150-200 feet apart, are you with me?
If this is not feasible for your particular setup then continue reading for two other suggestions that you can use.
Setting a different frequency for your vehicles
For this particular method, it is a simple case of identifying the car frequencies upfront, before you actually purchase the vehicles.
The idea is simple, buy two separate cars with different frequencies. For example, if you’ve got two children and they both want to have an RC Toy. Closely inspect what frequency of the cars before you purchase them.
In most cases, especially in North America, you will find that this frequency is either 27 or 49 MHz. Therefore, all you need to do is make sure you buy one vehicle which is set to 27mhz and the other vehicles set of 49 MHz.
Again, if this is not feasible for you, maybe because you have a need to have multiple RC cars (more than 2). Or maybe you’ve got more than two kids that require cars, continue reading for a third option that should help you.
This Final method for preventing interferences is probably the most effective way of doing it. However, it depends if the vehicle you have purchased has this option.
You can simply pick up vehicles that have selectable bands. These are selectable channels that will allow you to run multiple cars together.
Not every vehicle will explicitly say what the frequency is. They may use a colour coding system for each different channel. Or they may use a numbering system. Either way, it doesn’t matter, it is a way to change frequency and avoid interference.
Usually, you will see something along the lines of “this RC car is capable of running with two or more vehicles at the same time”, or something along those lines.
Effectively what will happen, for example, you may have two vehicles which are on 27mhz. But you can actually change the band (channel) so that they can run at the same time without interfering with each other.
In the background what is really happening is that each band or Channel has a slightly different frequency setting. It is still within the 27MHz range, but slightly different frequency, maybe .01 difference. But enough to avoid interference.
What happens to RC cars when there is interference?
As discussed earlier, in the US, RC Toys will typically have 27 or 49 MHz frequencies. If you only ever plan to have one RC vehicle in your household this is never really an issue.
But, if you have two or more than this, it can be a problem. This is because of the limited frequencies available for this grade of vehicle.
Effectively when you have two frequencies that Clash, for example, two 27mhz vehicles, what tends to happen is the radio waves get confused and can be picked up by the opposite vehicles controller.
For example, you may be controlling your vehicle and your friend or brother might be trying to control their vehicle at the same time.
However, during your race, you may find that your vehicle slows down or becomes completely unresponsive almost as if you are not controlling it. This is because the radio frequencies have got confused.
Do hobby-grade vehicles have more options to control interference?
Hobby grade vehicles have a lot more flexibility, with control for interference because you pay substantially more for them. They provide more options to avoid this happening.
For example, in some of the hobby grade vehicles, you will find that they have a crystal which can be configured to allow you to change the frequency that the vehicle runs on.
An example of this flexibility is for the 27 MHz range in these hobby grade vehicles, you may find that there are up to 6 or 7 channels. These can be selected to stop interference.
Understand that this is just an example of one MHz Range. There are also different MHz ranges to choose from. Each one has multiple channel options.
Meaning that the combination of settings makes it very easy to avoid an interference even if you were having a race with multiple cars
So how do RC transmitters and receivers work
To clarify for beginners, I’m going to explain exactly how RC transmitters and receivers work. So that you can understand how these frequencies work.
Firstly you have a transmitter and a receiver. The transmitter is the handheld remote that you hold in your hand. This can be a wheel or a stick.
The transmitter sends messages to the receiver using radio frequencies. The receiver is effectively a unit within the vehicle which picks up the signals via the radio waves.
The transmitter that sends messages to the receiver, using the radio frequencies, has a power source within the unit. This power source can be a simple 9-volt battery. This is used to control the vehicle and send the transmission to the receiver.
As discussed earlier, frequencies commonly used in RC toy grade vehicles are usually 27 or 49 MHz. These frequencies have been specifically allocated by the FCC for a few different devices. Not just for RC cars. This range is also used for operating garage doors or even simple walkie-talkies.
Difference between Remote and Radio Controlled Cars
The big difference between a remote control car and radio control car is the remote control itself. Remote Control cars are typically attached via a wire.
However, Radio control cars use radio frequencies to communicate. This often causes confusion, because, in this industry, the word RC is used interchangeably.
In addition to the standard settings of 27 & 49 MHz. In more advanced RC vehicles or even aeroplanes, you will find that they have more frequencies. For example, such as 72 or even 75 MHz. But these are more high-end models and you will typically pay a lot more money for these vehicles.
Can you change the frequency in your RC car? As discussed earlier, on toy grade vehicles, you will find that they have a set frequency that you cannot change. However, there are some that will have a selection of different frequencies for the same model. So, for example, you may walk into a toy shop and they will have a 27mhz version and a 49 MHz version.
Beyond this, in the older vehicles, at the hobby grade level, as discussed earlier, you will find a crystal inside. This can be paired with the crystal receiver in the vehicle. You simply swap out these crystals so that they can match up and provide a different frequency to avoid interference.
The new high-end hobby-grade vehicles have the ability to pair up with the receiver and change frequencies. These are usually more expensive models. However, a lot easier to do than having to fiddle around with the crystals manually.
Do you need a licence in the United States for the 50 MHz frequency? Yes, in the United States for the 50 MHz frequency band you do need a license for this. It is commonly referred to as the 6-meter band frequency. The Amateur Radio Community agree on the licenses. The frequency that is specifically reserved for this is 50.79 to 50.99.