Are Antistatic Work Surfaces EMF antennas? - Page 1
Forum section: electronics / general

author: Paul T
author_rank: Regular Contributor
timestamp: September 14, 2025, 02:35:35 pm
content: I was working on a boombox for someone and notices a lot of buzzing noise and poor reception. When I took the radio away from the grounded ULINE blue antistatic mat, the reception improved and the noise went down.The only EMF detector I own is a BSIDE S20. It detected high EMF on the left of the mat and low on the right side near the ground connection.The S20 generally detects moderate EMF around my new 2023-built home, but never detected general levels at my old 2008-built home located 7 miles away.I need to learn more about EMF. To some extent, I am concerned about general effects on our health. At my age, I don't need something contributing to reduced mental or physical capacity, already noticing a decline.Also concerned about unwanted effects while working on equipment. Is the blue mat I'm using an antenna for noise?

author: tom66
author_rank: Super Contributor
timestamp: September 14, 2025, 02:58:51 pm
content: Any large conductive surface can act as a part of an antenna. All antennas are effectively two pole devices (incl monopoles, the ground surface is the other pole). So anything sitting on top of that insulating surface will "see" the ground plane and there is an impedance between those two conductive sources so a voltage can form due to external fields. Of course, how effective it is depends upon all sorts of physical characteristics and the wavelength of interest.None of this makes any difference to EMF vs health. There is no substantial evidence to suggest EMF is linked to health issues but, even if it were, having an antenna in a location does not change the strength of the field unless something is driving that antenna. Think about it this way: if you take a photo in daylight, does the camera make the sun any brighter?

author: radiolistener
author_rank: Super Contributor
timestamp: September 14, 2025, 04:09:08 pm
content: It’s very likely that your mat is re-radiating noise coming from the ground connection. If the mat is tied to the household electrical ground, that ground is often “dirty”, since it also carries interference from other equipment in the house. In addition, because the mat is made of conductive material, it can itself act as an antenna. When you bring a radio close to it, you create capacitive coupling in the near field between the mat and the radio’s antenna. That explains the strong buzz and poor reception you observed.As for health concerns, there’s little reason to worry. Mains-related electrical noise is indeed high in today’s environment — modern homes are full of switching-mode power supplies and PWM LED drivers, and not all of them have good filtering. However, the field levels from such sources are usually below established safety limits. But from a radio-engineering standpoint, though, they can certainly create annoying interference, which is why you see such an impact on reception.

author: RJSV
author_rank: Super Contributor
timestamp: September 15, 2025, 05:29:43 am
content: We are surrounded by fields, all the time, and of usual very low intensity. Biological entities, like us, or mosquitoes, receive, and from a basic physics viewpoint, react, but it's such a minor, minor, degree of intensity, that it's really some (calculatable) value that has little everyday meaning.For the kinds of concerns many non-scientist folks express, it's bogus category, unless you have high frequencies, and higher voltages in virtually direct or very very close association.Folks expressly worried seem to, often, refer to their own concerns, as, ...comically; '...concerned about frequencies, getting in...'.X-ray technicians can, maybe, express the differences, safety-wise. But it's not 'frequencies', it would be called 'Field Strength'.