Graham-Stetzer Filters

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mxslick

Senior Member
Location
SE Idaho
I am inclined to think snake oil sales tactics in this case, based on two comments in that ad:

At 60 Hz the filters act as capacitors and normally marginally improve the power factor of the customer load, which are normally slightly inductive.

Residential users are not charged for poor power factor and the total contribution of poor power factor in resi is so small as to be insignificant.

and

...The preferred installation method is to be guided by the STETZERiZER Microsurge Meter, which measures the amount of high frequency energy present. Readings of 30 or lower indicate an acceptable environment, while readings of 50 or higher indicate a need for additional filters. Readings between 30 and 50 are marginally acceptable, but should be reduced if anyone in the area is electrically sensitive.

Hmmm, so you should use THEIR meter, measuring who knows what, (and who's to say that meter doesn't GENERATE noise that the filters will magically "cure"?) and what is "if anyone in the area is electrically sensitive" supposed to mean? :roll:

My BS meter is pegged on this one.
 

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100918-2107 EST

How do you judge a product like this? I think it would require a lot of double-blind experiments.

They do provide some technical information on the meter. This thing responds to the frequency range 10 kHz to 100 kHz. It measures the current thru an 800 pfd capacitor from line to neutral. 0.02 micro amps is 1 GS unit on the meter. A rough claim is that 27 GS units should be considered a maximum. But lower levels might be necessary for this criteria. Note: at 60 Hz, 800 pfd, and 120 V the current is about 45 microamps.

They seem to claim that there might be 800 pfd coupling to your body. This is a stretch. Standing on a cement floor and gripping in my fingers the probe of my Tektronix 130 LC meter the reading is about 40 pfd. Sitting on a metal Steelcase stool the reading is about 50 pfd.

If I was not touching a hot power wire and was instead in normal proximity to the 120 hot, then the capacitive coupling for current flow would be less than 40 pfd.

What does their filter do? It is probably a shunt capacitor across the receptacle. Also it is probably a very expensive way to place a shunt capacitor across the line. 1 mfd at 60 Hz is about 2650 ohms and at 10 kHz about 16 ohms, and 1.6 ohms at 100 kHz. The combination of branch circuit impedance from the high frequency source to the filter location would determine the attenuation of the high frequency noise.

I doubt that in most cases there is a problem to be solved.

There need to be some good scientific tests on humans to determine whether there are human problems that can be corrected by the filters operation.

You can probably make a lot of money from uninformed customers.


In contrast to this there is demonstrable evidence that either or both electric fields or magnetic fields can improve bone healing, especially where there is a gap between the bones to be reconnected. My cousin uses magnetic fields for some bone healing operations. A non-electrical solution in the case of one patient that was not healing was a visit to the patients home to see what the environment was. This kid, the patient, mostly lived on soda pop. Good nutrition is the most important factor in bone healing. Search the Internet for discussions of electromagnetic healing of bones. One site mentioned less than 100 Hz excitation in pulses at a rate of about 10 per second and about 0.1 Gauss levels. I did not find real good quantitative information on the subject. So electromagnetic fields can be good in some cases.

.
 

robbietan

Senior Member
Location
Antipolo City
"...close to the input power panel is recommended to address high frequency currents entering on the power lines...."

and where does these "high frequency currents" come from? the utility?

snake oil for sale
 

wirenut1980

Senior Member
Location
Plainfield, IN
They are measuring units that are not recognized by anyone except themselves. What is a Graham-Stetzer?

I have dealt with these guys before and it is snake oil for sale. They are preying on people who have some illness that maybe they think can't be explained and tell them millivolts of high frequency voltage is causing it and their device can make them feel better.
 

sameguy

Senior Member
Location
New York
Occupation
Master Elec./JW retired
Blind testing! How then do you know what is happening if you can't see?
Sounds like a diode and a capacitor in a box.
 
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