Looking for sources of Radio Frequency Radiation

The spectrum


Frequencies and wavelengths

Prof. Marshall posted: Sun Sep 21st, 2014 there are many ways that an electronic device can unexpectedly generate electromagnetic fields.

First, at low frequencies (<100KHz) you primarily get magnetic radiation Low RF frequencies are generally in the range 20Khz to 3MHz, HF (High Frequencies) are 3-30MHz, and VHF above that to about 500MHz. Cellphones operate in the 700-900MHz and 1800-2100MHz regions (some LTE is outside this range), NFC sensors are at 13.56MHz, smart electric meters are typically 900MHz (plus Zigbee WiFi), WiFi is 2.4HGz and 5GHz, and WiGig is at 60GHz.

The CWS systems have been at 6.78MHz, 13.56MHz and 27.12MHz

A month or two ago I started to revisit the topic of quieting down the appliances and adapters in my own house. What surprised me was the huge amount of noise emitted by the power adapters for charging USB, running Routers, etc. I ended up throwing most of them away.

The best way to see if a device is emitting electromagnetic signals is to use a Spectrum analyzer. This is basically a device which shows the entire frequency spectrum in one sweep, and some sweep all the way from 1MHz to 12GHz.

But a cheaper, and often more effective method, is to listen for interference using a shortwave receiver. Unfortunately, many of the receivers being sold in 2014 use a new digital chip which makes them almost useless for tracking down noise sources. I did find one radio on amazon which does work well, and is not too expensive (most of the 'meters' sold for this task cost hundreds of dollars). It is the WRX911 (or Tecsun R911 on Ebay). This is an old model now, and will eventually run out of stock. I am hoping that we are not too late to pick up those which remain, as the models which replace the WRX911 are DSP/digital, and terribly difficult to use as sniffers.

Joyful asks I just read that the technology used for USB 3.0 (Spread Spectrum) causes serious interference in the 2.4Ghz frequency. I guess Intel has published some research on this.

I see Amazon sells a lot of ferrite cores. How do these help?

Frenchie Since all devices with EM noise that are plugged into the mains will bleed over to the wiring around the building, exposure to EM radiation will be reduced by keeping house wiring away from beds and other areas where you spend most time. For an existing dwelling that is of course a major project.

Ron True. I am using a wireless keyboard and experienced a lot of trouble. In the end Logitech sent me a USB extension cord so I could place the receiver far away from those blue colored USB ports.


TM From observing the CWS systems we have seen that nanowatts of RF energy, containing a special characteristic found in Capacitors, seem to profoundly affect the human nervous system.

The problem is that we can't measure Capacitive Waves, and they cannot be easily picked up on normal radio receivers. At normal bioeffect levels, our 27MHz CWS system cannot be heard in a radio on the opposite side of a room. The “Tri-meters” sold for hundreds of dollars do not register a field near a 27MHz CWS. So we need to rethink the whole paradigm of “interference.”

Reading: Sacco and Tomilin: The study of electromagnetic processes in the experiments of Tesla Tomilin on waves : The Potential-Vortex Theory of Electromagnetic Waves

Exactly where is it coming from?

TM posted: Mon Oct 13th, 2014 DECT Telephones

Here is an interesting monograph from a German physician about her perception of an increase in illness perhaps due to DECT phone and Cell phone systems.

Dr. Christine Aschermann:“Observations from a Psychotherapy Practice on Mobile Telecommunications and DECT Telephones.“

We have a DECT-6 phone system, and the base unit is putting out frequent bursts of approx -30dBm energy. Which is higher than the WiFi I was complaining about in the Alaska Airlines aircraft, so, IMO, far too high a level. Its energy is centered in the 1920-1930MHz band, near the 3G cellphones, and not far from the 2440MHz used by WiFi and Bluetooth.

mvanwink5 I have two neighboring WIFI sources 70 to 100 feet away. One day i felt a change, a lifting of muscle symptoms, so it occurred to me to check the WIFI stations seen by my computer and lo, one of the stations was now off. Coincidental? Maybe, but something is knocking me around and cell reception is marginal here. There is my power meter pointed at my 5th wheel trailer, but somehow I suspect the WIFI'vers.

TM I know that the EMF-sensitive patient community gets really uptight about the magnetic field surrounding refrigerators, but honestly, I am sure their concern is exaggerated. I used to design refrigeration units and honestly, the compressor is encased in a welded steel can, a perfect faraday shield, and that really leaves the fan motors and wiring to be the primary radiators. Home power wiring is often radiating just as much magnetic energy. IMO, if you can get the remaining sources of everyday RF electrosmog down to the levels that the average refrigerator radiates, then you have been doing far better than anybody I know.

TM I would suggest starting to look over the spectrum for RF sources above -60dB in amplitude (that is around the 1 nanowatt level) There are plenty of them in my neighborhood, and were quite a few in my home. IMO, only once those have been knocked into shape is it worth going after the difficult power-line sources. The bricks and warts - sure, go for them - but laptops already start out pretty quiet from the factory…

My feeling at the moment, for my level of sensitivity, is: Solar and atmospheric radiation: not much you can do about this stuff. -60db or less: not much you can do about this stuff. -50dB is start of perception for me -30dB is a real problem above that, well, the Russian safety level is around -15dBm, and their scientists know a lot more about RF-bioeffect than I do… I do know that -20dB from standing in front of the microwave has been making me perceptibly ill - slow, headachy, hard-to-pin-down-stuff. Last week I was thinking that the caffeine from too many cups of tea was causing me problems - then I realized it was standing in front of the microwave, while the water boiled, which was messing me up.

We are all on a journey of discovery right now. Some members will not be sensitive to EMF.

Joyful If anyone is curious about various sources of noise on your home wiring, this very short video shows that the worst offender is compact fluorescent bulbs (CF) and dimmer switches.

TM Dec 2nd, 2014 This is the device which works best for portable spectrum analysis: RF Explorer

You need this 3G combo version, with the 15-2700 MHz wideband section, as well as the 220-960 that works a little better on Smart Meter radiation.

Here is the website of the designer: designer's site

This is an open-source project. Both the firmware and the interfaces to your Desktop software are open-source community based projects. The hardware is built by Seeed studio in China.

There have been rumors that a new version with a 6GHz upper frequency limit will be released within a few months, but 2700MHz covers all the cell-phone 4G allocations

David I travel to New Orleans for business a couple times a month and always stay at the same hotel. I always get massive leg cramps the first night of my stay and my sleep there is always poor. I've always thought that is was allergies or something in the air, or maybe the humid environment. But this past weekend, with help from my RF Explorer, a different picture is being painted. Here are some problem frequencies I found:

474,598 MHz, -45dB 477.767 MHz, -46.5 dB 512 MHz, -49 dB 515.633 MHz, -44.5 dB 528.483 MHz, -47 dB 601.383 MHz, -48.5 dB 604.553 MHz, -45.5 dB 645.758 MHz, -54 dB

They had me on the top floor this trip and it looks like there was a 4G antenna right over my head. Also, about a block away, I spotted a huge base station with a array of antennas.

I don't think there will be any safe place for me to stay in downtown New Orleans - just too congested. But the more I use CWS, the more I become aware of how sensitive I am to EMF. Perhaps I might need to reevaluate my ability to travel at all for the time being.

Joyful There are important sources you can identify without a meter:

any microwave ovens (and any close through a neighboring wall)
DECT (wireless) home phones
any wireless internet routers
any cell phone towers close by

There are measures you can take without a meter:

change out any CFLs
remove any halogen lamps
unplug all electronics on the circuit that feeds electricity to your bedroom

If we can do the best we can to clean up things in the area where we sleep/rest/heal, this is a big move in the right direction.

If we can protect our heads (brains/nerves) when out in the highly noisely world we live in using a hat such as the one Prof Marshall is working on procuring right now.

Then we will begin to learn to discern from our own body responses

k Can anyone recommend a wifi analyzer app from google play? Kevin Yuan's app doesn't appear to be available at the google store - so I'm assuming its from apple/iphones.

TM wifi.analyzer

TM you might be careful of the ISP's router, too. I just noticed that Verizon had switched back on the WiFi on my FIOS router. Luckily I had removed the antennas, in addition to disabling the software switch, but it still radiates an annoyingly strong signal. Sheez…

I am looking into EMF meters and such, so after tax season we might have some new suggestions on measuring and assessing the level of risk.

Liz and I just stapled 1/2“ wire mesh over the fence between our bedroom and the neighbor with the DECT phone which floods our house with signal. The wire mesh effectively goes about 8ft high, yet only cuts 10dB to 15dB of signal (which is nevertheless a welcome drop

vwmusum Oct. 2017 I just checked my house:

BASEMENT: -64dBm (sniffer silent even on sensitive setting)

1st Floor BATHROOM -64dBm (sniffer silent)

1st Floor BEDROOM -50dBm (sniffer slow beep)

2nd Floor OFFICE by DESK -30dBM (sniffer moderate beep)

2nd Floor OFFICE by COMPUTER -10dBm (sniffer high w/red light flashing by router despite turning off WiFi from Verizon and wrapping router in metal mesh cage and wrapping the cage in two layers of tin foil). Very frustrating despite my best efforts!


T Marshall Sept 2017 The problem with shielding in automobiles is that a very significant source of incoming radiation is from the “Driver Assist” Radar waves on 24GHz and 76GHz. These have proliferated recently, and represent a hidden, and very difficult to shield from, problem.

A sniffer will not sense either 24GHz or newer 76GHz radars at all. Nada. Neither will your Cornet. But the waves are there. Everywhere there are newish cars. Radiating from front, back and sides of the vehicles. The incident power levels on your face both from oncoming drivers, and the from the car you are tail-gating, are quite high.

Indeed, ignoring solid metal sheets and the inflexible yShield 'fleece,' the best attenuation is provided by window-film sheets. This is because they are made with an evaporated metal coating, with performance right up through to infrared frequencies, and micron wavelengths. The Safe Living Technologies SLT-1053 gives a clean 35dB attenuation at both the radar frequencies (and also down to the 4G cellphone frequencies as well). But how could I use this to shield my face?

First attempt - a 'Dental' Face Mask trial Dental Mask

Buying a face mask from Amazon, I used small pieces of gaffer tape to stick the film over the plastic cover of the mask. The problem is that the shielding film does not stretch, so I elected not to try and glue it to the mask's plastic and try to force it into a curve.

once a small blower fan is hung around my neck on 2mm elastic (fan is powered by the 12V car adapter) then my brain doesn't overheat Small fan

Easily packed shielding

I needed something which will pack easily in a carry-on roller-case. What I came up with also shields much better than the face mask.

from front

Here is a view from the side

from side

And the dimensions are shown on a background of one inch squares (measure your head circumference and test the sizing with a sheet of paper before cutting the plastic)

You will note that there is small cutout for the shoulders to allow the front to drop a little lower and protect more of that important neck area. You will also note that it folds flat along the seams sealed by the copper tape.The metal tape is not important, it needs no conductive adhesive. I put the protective plastic covering side of the film on the outside of the tube so that my nose will rub on the stronger polycarbonate/ polyester interior surface.

With the blower fan (obligatory) this tube works really well indeed, giving shielding to the brain and brain-stem (upper neck) from all directions. OK, so I look like a dork - who cares, I am free to comfortably travel long distances again

BMW started to use RF-reflecting films on their car windows about 15 years ago. There were so many complaints from people who found their cell phones didn't work inside their cars that the protective coatings were left behind as the years have rolled by.

If your state allows windows to be tinted then go for it, I would do them all. The Safe Living Technologies film is good for 35dB, and 78% light transmissionAn incident in which an infectious disease is transmitted., but it doesn't like being applied to curved surfaces…

Here in California there is nothing allowed on the front window, the primary culprit…


From: Prof Trevor Marshall Date: 2015-02-09 17:41:12 Reply: https://www.marshallprotocol.com/reply.php?topic_id=16133

Sherry, you might be careful of the ISP's router, too. I just noticed that Verizon had switched back on the WiFi on my FIOS router. Luckily I had removed the antennas, in addition to disabling the software switch, but it still radiates an annoyingly strong signal. Sheez…

I am looking into EMF meters and such, so after tax season we might have some new suggestions on measuring and assessing the level of risk.

If you look at the WiFi screenshot from the WiFi analyzer you can see it covers from -20dBm at the top to -100dBm at the bottom, a range of 80dB, or 10**8 (which is 100000000:1). It is easier to think in dB than decimals, trust me :)

Generally your WiFi and cellphone will get a good signal below -74dBm, and humans will get affected above -74dBm. Some higher, some lower, of course, and some not affected at all. So -74dBm is the sweet spot, at least based on what we know so far. None of us has managed to get background levels down that far yet. I am hoping that when I paint a room with conductive paint on walls and ceiling (the floor is a concrete slab) I should be able to achieve -75dBm. That is a work in progress.

Liz and I just stapled 1/2” wire mesh over the fence between our bedroom and the neighbor with the DECT phone which floods our house with signal. The wire mesh effectively goes about 8ft high, yet only cuts 10dB to 15dB of signal (which is nevertheless a welcome drop :) )

- Trevor Marshall

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