Disorders
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Many of us experience disturbances and high noise levels, especially if you are in a densely built-up area.
I've had the same problem and here I thought I'd share some of my experiences how to fix the problem.
I start by dividing the disorders into 3 categories, but it can also be a combination of these.
Category 1are disturbances that come from one's own household, which are the easiest to deal with.
To make sure that the interference is coming from your own home, start by turning off all incoming power to your own home and running the radio on battery.
Turn off the main switch, remove or switch off all fuses and also remove incoming main fuses to try to stop any interference coming in via the mains.
If the interference is gone after that, start by screwing in the main fuses, turning on the main switch and then screwing in or turning on one fuse at a time until the interference returns.
This way, you can see from which group the interference is coming from.
Search the relevant group by disconnecting one consumer at a time until you find the source of the interference.
If it is difficult to eliminate the source of interference, changing the phase of the drive of the station can help.
The power supply can also be the cause of the disturbance.
Category 2are disturbances that come in via the power grid.
This is usually noticed by the level of interference increasing when you screw in the main fuses and turn on the main switch, even though all consumers in the home are disconnected and the radio is running on battery power.
By taking a radio out connected to a simpler loop antenna, you can usually follow the disturbance by listening to the disturbance following the incoming cable. Get a map showing where the cable is laid in the ground if it is not overhead and follow it with the radio to see if the interference is coming from the cable.
If this is the case, contact your network provider who will help find the source of the interference.
If it is difficult to eliminate the source of interference, changing the phase of the drive of the station can also help here.
Category 3are airborne disturbances from the neighborhood.
They are often quite local and to find them you take a radio out and look for the disturbance in the immediate area.
You can often see where it is strongest by moving in different directions in the neighborhood and that way call in from which property or area the disturbance is coming from.
It is best to talk to the owner of the property where the disturbance seems to be coming from and together do a fault finding according to category 1 with the property owner.
You can also use the help of the Swedish Electrical Safety Authority to search for the disturbance.
If you find what is causing the disturbance, offer the owner of the source of the disturbance to replace it.
If it is something that is expensive or complicated to replace, the Swedish Electrical Safety Authority usually gets the manufacturer of the interference source to fix the fault.
Often, the disturbances outside one's own household are a combination of Category 2 and 3, but the network provider and the Swedish Electricity Authority usually help free of charge.
If the interference is reasonably strong, it can often work to look for the interference outdoors with a normal transistor radio tuned to the AM band.
What is the acceptable noise level in a densely built-up area?
The disturbances usually vary with frequency and are mostly worse on the low bands.
If you have a noise level between S5 and S7 on 160m and 80m, you should be satisfied if you live in a built-up area.
If the noise level is closer to S9 or above, there is reason to start looking for sources of interference.
Many of the disturbances in densely built-up areas usually become weaker at higher frequencies and on 10m an acceptable level is S2 - S3.
It is of course easier to deal with the disturbances if you live in residential areas.
If you live in an apartment building area, it can be very difficult to find the right one and then the only solution might be to run the station remotely if you have that option.
There is also an aid in the form of aQRM eliminatorwho help many.
It is based on having another, simpler antenna that receives the interference.
The eleminator then reverses the phase of the interference and thus phases it out, which can be very effective in certain types of interference.
On the link below you can see a video when I functionally test a QRM eliminator that I had for repair.
Test of QRM eliminator
There are also amateurs who have solved the problem by various modifications to the antenna system. Unfortunately, I have not succeeded in reducing the interference to an acceptable level.
Tips regarding interference mitigation measures in the antenna system are gratefully received and published here.
Here you can read more about how to deal with disturbances. The document was produced by SM7EQL Bengt Falkenberg - the Association of Swedish Radio Amateurs.
Click on the PDF button to view the document.
More information is also available on ESR's website, click on this link to get there:https://www.esr.se/index.php/emc-och-stoerningar
Also visitham.seand look under the disturbances tab where there are many threads on the subject.
In conclusion, a description of the cause and effect of disturbances, published by SKEF-News and written by Per Samuelsson, Swedish Electrical Safety Authority.
Good luck dealing with your disorders and feel free to give feedback if you find other ways to get rid of your disorders.
When electronics interfere with radio traffic
The development of power electronics and digitization means that more and more products are at risk of producing unacceptable interference. Power electronics are being developed to become more energy efficient, therefore faster switching frequencies are used which require more advanced and more expensive filters to not emit electromagnetic interference.
Because the costs of effective filters are high, it is not always a priority.
The disturbances spread partly via wires and partly through the air to other devices that are affected.
It is often difficult to understand what causes disturbances, how they manifest and what is affected.
Legislation and standardization are slow processes that do not always keep up with the rapid technological development.
This means that manufacturers have to take a big responsibility to carry out comprehensive risk assessments.
If the protection requirement is not addressed in the legislation of harmonized product standards, manufacturers must find other ways to demonstrate that the requirements are met.
This may mean that manufacturers need to turn to a notified body for help with the assessment, selection of standards or finding alternative test methods.
In the case of large installations such as solar cells, fan controls and speed-controlled motor drives, special consideration must also be given to the design of the installation, how cables are laid and the use of correct interference protection.
Installation must follow the manufacturer's instructions to meet the requirements.
When it comes to installations with high effects, which are also mounted on roofs, the problems can be very large and spread over large distances.
There are examples of severely affected radio communications or disrupted flight navigation systems.
This type of problem is often very difficult to solve afterwards and can lead to high costs.
But it is not only large installations that cause disturbances.
We see that smaller and cheaper electrical products cause a lot of disturbances, usually they are power supplies, battery chargers and light sources with LED technology.
The disturbances are spread via wires when filter components age, it can be electrolytic capacitors in mains filters that dry out or other components that lose specified tolerances.
This can cause a lot of problems.
Inexpensive consumer products may also have no filters at all or may not even be designed to meet the requirements set in the EU. The problems with smaller products, on the other hand, are usually local, the disturbances affect other electrical products nearby and rarely spread beyond neighboring properties.
However, they can be very difficult to understand and locate.
Is it your old TV that is breaking down or is it the neighbor's electric bike charger that is disturbing it?
The Swedish Electrical Safety Authority has recently received an increase in resources to develop work with EMC, electromagnetic compatibility, and is building a more efficient organization around these issues.
Disruption problems are often complex and we depend on notifications about the problems to be able to carry out effective supervision.
The investigations are complex and take time, therefore it is important that we have a good organization and good cooperation with other authorities, companies and users.
Per Samuelsson, Electricity Safety Board
