Noise Canceller Kit – from VK5TM

With thanks to Phil VK3VB for this case study Early March 2020 saw me working from home due to COVID-19.  This led to re-establishment of the long-neglected shack, which was also the home-office.  First, the digital modes were re-established with DSTAR, DMR and NXDN along with the standard 2m/70cm FM. Over the past few years, […]

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Plasma TV RFI – symptoms & possible cures

Thankfully, not many people have plasma televisions these days.  However, if you are unlucky enough to own one, or a neighbour still owns one, this is what you can expect to see and hear.  The radiated RFI will be broadband and may extend from 160m up through the HF bands.  It is likely to be […]

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The truth about ferrites

These tests and experiments were performed by Ian Jackson VK3BUF in the QRM Guru test lab. Much has been said about the importance of applying ferrite clamps, rings and beads to radios and other domestic products to fight QRM. Articles on the correct placement of ferrite noise suppressors are common, but little has been written […]

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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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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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Nothing has worked. I still have S9 noise.

Well, you’ve tried everything.  You have been unsuccessful in resolving your noise situation.  Send us an email with all the details of your scenario and we’ll see if we can provide any further ideas.  Please ensure you’ve followed the processes, tools and techniques before you contact us. feedback@qrm.guru There are a few options to consider; […]

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Lodging Complaints

If you are unable to resolve your noise issues yourself, it may be necessary 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. Engaging the ACMA should be a LAST RESORT.  If you feel […]

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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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