on stetzer filters

http://conradbiologic.com/articles/EMFscams.html

3. STETZER FILTERS
The Stetzer device is a capacitor-type filter that does remove some of the powerline noise, but only differential mode noise below 100 KHz. Many vendors of these filters are either ignorant or dishonest because they claim it eliminates most of the noise, and they base this conclusion on readings that they obtain with the meter they sell with their device with the meter plugged in next to the device. The problem is that their meter only measures the type and frequencies of the noise that they remove (differential mode noise below about 100 KHz), but does not measure the type that they don't remove (differential mode noise above 100 Hz, and common mode noise). Furthermore, the way that the Stetzer filters remove some of the differential mode noise is by converting it into additional common mode noise (which they don't remove), and they are not very effective at a distance from the outlet where they are plugged in.

Almost all computer-generated noise and switching power supply noise is at a much higher frequency than 100KHz. Stetzer filters aren't effective above 100KHz. Stetzer filters are used by plugging them into outlets throughout the house. But if the source of the noise is from within the house (such as computer equipment), the noise needs to be filtered out between the equipment and the outlet, before it reaches the outlet. If the noise comes from outside the home, filtering is best applied before the power enters the house. Although the latter would cost thousands of dollars and the Stetzer filters are far less expensive, this does not mean that Stetzer filters are an alternative that can have any significant benefit. The Stetzer filter is not a very effective filter. Any effective filter uses multiple stages of inductance and capacitance. Even the cheapest of computer filters employ both inductance and capacitance. The Stetzer filters do not use any inductors, only capacitors. Even in the very limited range that these filters operate (only differential mode noise and only between 4 and 100 KHz) the reduction is very small compared to the amount necessary to make a real difference for electrically sensitive persons - the noise reduction is only about 10 or 20 dB (see section 4. D) below), and it does nothing to common mode noise. Many electrically sensitive people have reported no benefit from Stetzer filters. And of course, powerline filters do nothing for ground currents or for emissions radiated directly from devices. The Stetzer filters can only be of benefit in situations where most of the noise is of the differential mode type and is below 100 KHz.

I learned about Stetzer filters the latter part of 2014 and after reading about them and thinking about ordering them, I finally ordered the basic 7-filter and meter set about a year later. So it wasn't a hasty purchase. After the filters had been plugged in for a time I knew I was feeling worse. Ultimately, I was getting these little pink bumps mainly on my forearms, then a rash on my left hand. The bumps nor the rash hurt. I felt worse too after having the filters plugged in. I think I had the filters for about two months, it may have been less.

After the filters were gone, the rash and bumps stopped appearing, what was there ultimately disappeared and I felt some better but still plagued by electro and radio frequencies and still am today.

About the filters, I consider myself very fortunate that the company I purchased the filters from took them back, no questions asked.

It is too bad sellers aren't more knowledgeable regards product they sell.

I have been told greenwave is better? I have some stetzer and green wave filters but I have no idea if they are really helping.