QRM Guru Lab – Product Reviews
One of the new challenges to Amateur Radio is being able to deal with electrical noise that comes from domestic light fittings and electrical appliances.
Sometimes the interference comes from neighbours and sometimes from our own equipment. It is very difficult to purchase domestic appliances and be sure that they won’t contribute to local noise levels on HF and VHF.
An ongoing QRM Guru initiative is to review and report on a range of common appliances and see if they are Amateur Radio friendly.
Each item is powered up inside a shielded enclosure (an old Philips Microwave Oven) and the interference profile is measured on a spectrum analyser operating between 1 and 150 MHz.
The result is placed on a score sheet where the impact on each band from 160 Metres to 2 Metres is scored on a scale from zero to 10, where zero indicates no noticeable noise and 10 approximates full scale noise readings on a receiver signal strength meter.
A typical example indicates the RF noise generated by a 12 Watt down light which makes a mess of signals on all Amateur bands from 80 metres through to 6 metres.
A sample of LED downlights has been performed. You can view the results here. This library of interference reviews will be expanded over time.
It is important to note that these are subjective reports taken from a small product sample and individual results may vary. Purchasers and users of these products should form their own conclusions about the appropriate use of any items reviewed in these reports.