DF Loop kit and noise cancelling techniques

The following case study sourced from Grant VK5GR One thing I have found very helpful for finding sources is to build this kit: https://www.minikits.com.au/electronic-kits/high-frequency/hf-active-antenna/EME234-HF-Active-Loop Click this link to visit minikits website. For the antenna, get some ½” soft copper pipe and form  a loop about 30cm diametre and use that in place of the wire […]

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The best thing you can do to reduce noise in your radio shack

We’ve spoken about the importance of having good house-keeping in your goal for a low noise environment.  Other posts on QRM Guru talk about various techniques and tools you can use, but in this video Peter, VK3YE provides a great practical demonstration of how you can reduce noise in your shack.  Using Ferrite rings and […]

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Using Chokes & Filters to suppress noise – a great reference

A VK6 member found this very useful reference on noise suppression.  Full acknowledgements to G8JNJ. Whilst this document has been written from a UK perspective, it is very useful for: noise suppression in consumer appliances & switch mode power supplies reducing noise in the shack using ferrite rings to suppress noise understanding RFI G8JNJ Notes […]

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Tracking and resolving Garage Door Controller noise – noisy PSU

Another noisy garage door causing havoc on HF. A  group of hams decided to use QRM guru to help with some unknown RF noise.  Using the DF Loop the garage door opener was found to be the cluprit The garage door controller was removed and taken to the workshop for further analysis. Model Herculife RDO-V12   […]

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Tracking and resolving Garage Door Controller noise – software setting

Thanks David, a VK3 amateur for this article. Like many amateurs, I live on a suburban block surrounded by local neighbourhood RF hash.  My noise level on 40M was typically S9 plus with crackling interference. In the past the basic checks were completed, LED lights, solar inverter etc and without any real conclusion, I became convinced […]

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Kill QRM Kit – Information Sheet and Video

This information sheet  and short video are excellent starting points for the equipment needed to find and resolve interference issues. It would be useful to supplement this kit with other items, such as a general coverage portable receiver, an audio recording device and a camera.  Many operators already have these items at their disposal.   Go kit […]

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Nothing has worked. I still have S9 noise.

Well, you’ve tried everything.  You have been unsuccessful in resolving your noise situation.  There are a few options to consider; all these are taken from real world scenarios: Try out digital modes.  Due to their narrow bandwidth and protocols they are often less impacted by a poor signal to noise ratio Consider taking your hobby […]

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Lodging Complaints

If you are unable to resolve your noise issues yourself, it may be neceassry to lodge a complaint with third parties or the regulator.  Watch the video on this page to gain a better insight into how you’d go about making a formal complaint. If the noise emanates from main power infrastructure visit the post […]

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Using baluns to minimise noise

Whilst a balun is usually associated with reduced unwanted transmission line radiation (eg. from the feedline and power cord), a balun can also help minimise unwanted noise picked up by your feedline.  This short video provides a practical demonstration.  With thanks to Davide IZ2UUF. You can purchase commercial baluns or make your own.  There are […]

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Using grounding to minimise noise

Good RF grounding should provide a low resistance path to ground for any RF noise which is present. A low resistance path to ground ensures that the noise is conducted away to ground instead of being radiated.  In addition, your station should also have a quality low resistance path to ground. Refer to this link […]

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