Tracking down interference in the 2m amateur band

This success story is from Andrew, VK3FS.  Thanks Andrew… Whether it’s an annoying buzz or hum, radio interference can certainly diminish enjoyment of our hobby. Finding it and getting it fixed can be one of those challenges that can really try us, but it need not be. This is the story of my local QRM […]

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Newcomers start here

Are you new (newbie, FL) to Amateur Radio and don’t know where to start?  Start here… If you’re new to Amateur Radio you’re likely overwhelmed with all manner of information and options on where to start.  More than likely, if you live near a city, or in the suburbs, and you operate on HF, you’re […]

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List of Tools

Here is a simple list of tools you’ll need to start searching for noise: a small DF loop, like this one for VHF and UHF, a Yagi or other directional antenna. Say something around 8db gain a simple wide band AM receiver or a 2/70 handheld for higher frequency work the new Nano VNA could […]

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LED Down lights – resolving a significant noise problem

Thanks Steve VK5SFA for this article. Sometime in late July 2019, a strong wideband noise appeared across all HF bands at my home QTH in Adelaide.  The noise level was S9+20dB (-50dBm) and was making HF reception from my suburban block almost impossible. I started the process of remedying the situation by logging the interference […]

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Locating noise in your home

If your noise source is limited to your home (and property) then you’re in luck.  You have much greater control over how the noise can be resolved. Follow this simple procedure to locate the noise. Power your receiver with a 12v battery so you’re independent of the mains supply You can start by turning off […]

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Locating Power Line Noise

The below videos give a real world example of power line noise suffered by Allan VK2CA.  The second video shows first hand how you can use a simple VHF/UHF receiver to narrow down the offending power pole.   QRM.guru thanks Allan for providing these videos.     This video illustrates first-hand the horrible sounds that […]

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Narrowing down the offending noise source

Now you’ve spent some hours playing detective and believe you have a good handle on the location and source of the noise.  For example: The two adjacent neighbours are radiating significant broadband noise, indicative of switch-mode power supplies, as well as what may be an auto battery charger. You have also identified some powerline noise […]

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Step one to locating the noise source

Once you have undertaken some basic analysis of the noise source (from the comfort of your shack) you should have a basic understanding of its characteristics. You will also have completed the following templates in order to assist in narrowing down and locating the noise source: Noise Profile template Noise Log template     You […]

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How to locate the noise source: building a DF Loop

To locate the noise source, you’ll need some tools.  This short video explains how to build a simple non-resonant direction finding (DF) antenna. It would also be useful to have a broadband receiver covering 100KHz to 1GHz, for example the ICOM T90A.  As always, dont forget to make notes as you carry out your detective […]

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Identifying the noise – Useful links

This post provides links to some useful sites and resources to help you identify your noise.  Please send us any additional resources or links you know about. Two common and sometimes misunderstood terms (or Q-codes) are QRM and QRN.  The images below provide a high level explanation of the difference between QRM and QRN. This […]

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