If you are an amateur ham radio operator then you would want nothing else than to have a clear signal whenever you power up your rig. However, that is not always the case most of the time. It is even impossible for you to switch on your radio without experiencing the noise of varying degrees.
If you want to know how to stop ham radio interference, you need to first have an idea where they came from. By knowing all that information, you can make your hobby run smoother than before. Two sources of noise that are likely to cause interference with your ham radio rig are electric and electronic.
Electric noise comes from the electricity arcing in power lines or within electric equipment such as motors, heating elements, and electrified fences. On the other hand, electronic noises come from RF signals leaking out of consumer electronics and quite possibly, from computers that are being used nearby.
How to Stop Ham Radio Interference?
Each type of noise has a signature sound and the following list of different signatures of electric noises:
1. Power Lines
These produce a steady but sometimes intermittent buzzing noises of around 60Hz to 120Hz. In most cases, bad weather will cause interference to become more prominent.
Power line noise is the result of electric arcing or corona discharge. Arcing can happen around and even inside cracked or damaged insulators. This also happens when two wires, such as the neutral and ground wires, accidentally rub against each other.
Corona discharge often happens at the high-voltage points on sharp objects where the air becomes so ionized that the electricity tends to start leaking out to the atmosphere. The interference often causes a 120Hz buzzing sound because the arc occurs every time the electricity hits 60Hz, which happens twice every cycle.
If you think that a problem in the power lines near your home is the reason for interference in your ham radio, never attempt to fix it on your alone. You should always contact your local power company. Aside from being extremely dangerous for you to do so, it is also against the law.
You might be slapped with a hefty fine when the authorities get wind of what you did. Instead of trying to fix the problem alone, you can just assist the power company by finding the source of interference, which is most likely faulty equipment. You can do so by using a battery-powered AM radio or a two-way handheld radio with an AM mode.
Use either of the two when walking alongside the power lines near your home. The point where you notice that the interference is the loudest is the specific place where you can locate the problem. Alternatively, if your radio has a rotating antenna, you can use it to find the general direction of the electric noise.
You can also drive along the road beside the power lines with the car’s AM radio set between stations. This is the point where you can only hear static noises. Once you find the offending pole that is most likely the cause of your electric noise, keep your distance from it.
Take note of anything that might seem like an identifying detail, like any number or distinguishing graffiti. It should be anything that will help the power company find the pole easier. Contact your local power supplier and tell them what you found, including the numbers and identifying marks on the electric pole to help them find it faster.
2. Industrial Equipment
The electric noise that comes from industrial equipment sound similar to what you get from power lines but they have a regular pattern, like the electric motors or heaters that operate according to a cycle.
Some of the things that might produce interference are vacuum cleaners, furnace fans, air conditioning motors, sewing machines, and others.
3. Defective Electric Contacts
If you hear erratic buzzing and rasping sounds, they are most likely caused by failing thermostats or electrical switches that are carrying heavy loads. These are the kinds of things that you need to be concerned about.
All these noises come from a legitimate fire hazard in your home, which is important to fix immediately.
4. Dimmers and Speed Controllers
If you hear a noise that is similar to those coming from power lines but they tend to come and go at seemingly random times, they might be coming from appliances with dimmers and speed controllers.
5. Vehicle Ignition
You might even get interference when someone starts their car engine nearby. This is indicative of buzzing noises that vary with engine speed. The noise comes from the electricity arcing in the ignition coils.
6. Electric Fences
If you hear a regular popping noise that comes at around 1-second intervals then this noise can also be caused by a defective charger. However, often, the noise comes from broken insulators or the electricity arcing from the fence wires to the nearby bushes or branches.
Locating an in-home source of electric interference will depend on whether the device causing the noise is inside your home or at your neighbor’s. Tracking down the source from within your home is simple. Just recognize the noise pattern and look for the appliance or source that causes it.
Another way is to systematically turn off your house’s circuit breakers one at a time to find out which of your home’s circuit is causing the electronic noise. Once you find which circuit causes the noises, check every device connected to it for signs of problems.
If the noise is not coming from inside your home then you have to find out the direction of the source and start walking in that direction while carrying a portable receiver (which is just a battery-powered storm radio with an AM mode).
After finding out which house the electronic noises are coming from, knock on the door and inform the homeowner of your findings. The noise might be coming from a potential fire hazard so they need to know that their lives and property are in danger.
Regarding electric noises, the following list describes the common sources:
- Desktop computers, videogame consoles, and home networks – These electronic devices usually produce a steady or warbling sound on a single frequency that is strongest on HF but can also be heard at VHF and UHF bands.
- Cable and power-line modems – These produce either steady, warbling or hissing/raspy tones on the HF bands.
- Cable TV leaks – Cable television signals that leak into VHF and UHF are like buzzing sounds. Sometimes, they sound like audio FM signals with content, too.
- Plasma televisions – Some Plasma TVs are RF-quiet but many models still produce noises across a wide spectrum of radio frequencies, especially the older models.
The only solution for this problem is to just replace the plasma televisions with modern LCD or LED televisions that do not cause any RF noises whatsoever.
Different types of electronic interference will need their unique set of techniques for locating the source and stopping the noise. Your radio will likely receive interference coming from electronic devices within your home or somewhere close by because of the weak signals.
If you find that the sources of the noises are not within your property, you can find the source by walking around your neighborhood with a portable AM radio.
What is the Difference between HAM and CB Radio?
Ham is the term used for describing both the type of amateur radio used and its operators. Ham radio can only be operated by people who understand how radio works. To make it easier to regulate, the government issues licenses and official call signs for Ham radio operators who can pass the licensure examination.
On the other hand, citizens’ band (CB) radio is open for use by the general public, regardless if they are licensed radio operators or not. The CB radio is hardly regulated by the government and you will only need to get a license if you plan to operate your radio station.
In terms of hardware used, there are many differences between Ham and CB. By law, CB radio operators can only use equipment that can transmit at 5 watts, compared to that used by licensed Ham operators that can transmit at power levels reaching 1.5kW.
Power levels are directly proportionate to the distance that the radio operator can broadcast to. This means that ham radio operators can use equipment that is powerful enough to transmit signals across the world while CB radio can only transmit at a couple of miles around.
Ham radio operators also have a wider choice when it comes to frequency bands they can use. The CB radio, on the other hand, can only use a 27MHz band. Because of the frequency restriction, it also greatly reduces the applications that CB radio can be used for.
By contrast, you can use Ham radio for virtually anything, which includes television, microwaves, satellite communications, and even high-speed data communications. Finally, ham radio users (the licensed ones) can legally build and repair their rigs.
It is mainly because they have intimate knowledge of how radio works. CB users are not allowed to do the same as the equipment can be used to break the law.
If you want to know how to stop ham radio interference, you need to be a licensed ham radio operator. Also, you constantly need to have your wits about you. If the situation seems dangerous, just walk away and let the professionals fix the problem.
Richard Pennington is the one to consult when you need professional insight into electronics. With over a decade of experience in the field of electronics and communication engineering, he now serves as our chief content editor.
He is an advisor for multiple articles and videos with topics revolving around ham radios, electronics devices, and communication.