Electrical fields on AC wiring

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fields5491

Member
I have noted electrical fields at 45 Hz(150v/m) and 75Hz(50v/m) measured in the air near light switches, measured with a spectrum analyzer. The same analyzer measures a 60Hz efield of about 200v/m.
Does anyone have suggestion as to source? (Screen shots available).
Thanks.
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
090602-2202 EST

Maybe 15 Hz modulation on the 60 Hz carrier.

Do a spectrum analysis of the AC line directly. Look at the AC waveform on a scope.

.
 
H

hurk27

Senior Member
Location
Portage, Indiana NEC: 2008
I take a stab at it, electronic fluorescent ballast are at 20k give or take a few Hz, so the 45Hz could be a second harmonic?
75Hz Dimmer, switching power supply or a harmonic of it???? No clue

A high field of 60 Hz could indicate switch loops run away from return current conductors, single wire feeds, basically circuit's not having the conductors ran together that would normally cancel out the EMF. typically a violation of 300.3(B) but not always. I have used a spectrum analyzer as a tracer using a simple loop antenna, to track other EMF's before? but at this frequancy area of the band it would be one heck of a loop:D
 
ELA

ELA

Senior Member
Occupation
Electrical Test Engineer
--------------------------------------------------------------------------------
Are you still using that same "Spectrum Analyzer" that is not a toy?


http://forums.mikeholt.com/showpost.php?p=902911&postcount=16

I suspect the analyzer itself. Especially if these switches are sources of higher (RF) frequencies that might interfere with the accuracy of your field strength meter.
 
H

hurk27

Senior Member
Location
Portage, Indiana NEC: 2008
ELA said:
--------------------------------------------------------------------------------
Are you still using that same "Spectrum Analyzer" that is not a toy?


http://forums.mikeholt.com/showpost.php?p=902911&postcount=16

I suspect the analyzer itself. Especially if these switches are sources of higher (RF) frequencies that might interfere with the accuracy of your field strength meter.
Click to expand...

A Spectrum Analyzer is not a field strength meter, although can be used as one in a broad sense, in general it is a sort of scope as per say that allows one to view/log a wide band of frequency's at the same time showing the levels of signals at different frequency's, I have had several over the years and even had some that I could add a am detector diode module, or a Deviation detector (FM) or a BFO, to listen in on what it was picking up, good tool in tracking down EFI problems.
 
ELA

ELA

Senior Member
Occupation
Electrical Test Engineer
Yes I have owned and used both over many years while performing EMC compliance testing.

I was questioning the OP for the model number in the referenced previous thread in order to help determine the specifications and the quality of this "Spectrum Analyzer".

I suspect the analyzer itself.
 
ELA

ELA

Senior Member
Occupation
Electrical Test Engineer
hurk27 said:
I take a stab at it, electronic fluorescent ballast are at 20k give or take a few Hz, so the 45Hz could be a second harmonic?
75Hz Dimmer, switching power supply or a harmonic of it???? No clue
Click to expand...


45Hz is a second harmonic of 20khz?
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
090604-0718 EST

When you AM modulate a carrier frequency with a sine wave you get upper and lower sidebands that are the sum and differences of the carrier and the modulation frequency. If the modulating waveform is non-sinusoidal, then there are lots of other sidebands.

As I indicated in my earlier post a 15 Hz modulation frequency would produce the 45 and 75 Hz frequencies.

Note: 15 Hz is exactly 1/4 of 60 Hz. Does this have any significance?

.
 
ELA

ELA

Senior Member
Occupation
Electrical Test Engineer
Interesting thoughts on side bands Gar,

Is my analysis along the correct lines?

Given the OP's data that he measured approx 1/2 the level in the possible side band frequencies (45 and 75hz) as the carrier (60Hz).

Would we talking about approx. 100% modulation such that we are looking for a 15Hz signal at roughly 120vac ?
 
F

fields5491

Member
Hi, thanks for the reply's.
The analyzer is made by aaronia (http://www.aaroniausa.com/spectrananalyzers.shtml)...model 5010, not a toy. I am looking at the electrical field, not the magnetic component. The magnetic component is not seen at 45 and 75 hz, however, the m-field around 45 and 75 hz is seen to pulse and approach zero at specific frequencies near these frequencies ( unusual and further questions arise on this, perhaps later).
The AC line does not have fluorescents or dimmers.
Additional thoughts?
 
F

fields5491

Member
Yes this is a residential location. The amplitude of these 'sidebands' decreases as the probe is moved away from the light switch. I have other interesting data on this same circuit. An AC power quality line monitor that logs voltage and frequency events notes large numbers of voltage transients.
These are seen to be variable, i.e. it has been logged that there are 24 hour periods when there are no voltage transients where normally this circuit notes MANY voltage events. Thus, I do not believe there is a problem with the line monitor. I will try to post the log below showing transients; it has been hypothesized that the 60hz is carrying an AM signal and your suggestion of sidebands is connected. What may be involved is "carrier current" of an AC signal. Thoughts on this?

Location: ACscout
S/N: 3371 Version: 3.04a
Voltage limits:123/117 Frequency limits:60.1/59.9 Temperature limits:90F/40F
=========================================================
05/31/2009 07:30:17 PM event=FREQUENCY LOW ALARM 59.9Hz temperature=70F
06/01/2009 12:28:43 AM event=VOLTAGE HIGH ALARM 123Vac temperature=72F
06/01/2009 12:36:30 AM event=VOLTAGE NORMAL 121Vac temperature=73F
06/01/2009 01:00:00 AM event=VOLTAGE NORMAL 121Vac temperature=72F
06/01/2009 07:12:44 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 07:13:31 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 08:09:45 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 08:10:37 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:03:58 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:03:59 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:04:06 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:04:07 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:08:45 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:09:52 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:50:21 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:50:22 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:50:23 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:50:25 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 10:50:33 AM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 10:50:34 AM event=VOLTAGE NORMAL 121Vac temperature=71F
06/01/2009 12:39:00 PM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 12:43:45 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 12:44:18 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 12:44:19 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 12:46:54 PM event=VOLTAGE HIGH ALARM 123Vac temperature=71F
06/01/2009 12:50:35 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 01:03:03 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 01:07:08 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 01:16:22 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 01:16:46 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 01:22:48 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 01:23:01 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:04:48 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:04:48 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:07:05 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:07:10 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:08:41 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:08:42 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:09:36 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:09:40 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:14:46 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:14:46 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:14:50 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:14:51 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:27:02 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:27:45 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:29:51 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:30:36 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:31:24 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:31:26 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:35:30 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:35:53 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:39:13 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:42:01 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:47:31 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:47:31 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:47:33 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:47:34 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:57:12 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:57:17 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 02:57:19 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 02:58:21 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 03:12:24 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 03:12:28 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 03:19:01 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 03:19:01 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:20:52 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:22:31 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:23:20 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:32:20 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:34:20 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:34:36 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:34:40 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:35:15 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:38:18 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:39:07 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 04:39:42 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 04:45:26 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 05:01:22 PM event=FREQUENCY HIGH ALARM 60.4Hz temperature=70F
06/01/2009 05:01:23 PM event=FREQUENCY LOW ALARM 59.9Hz temperature=70F
06/01/2009 06:30:59 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 06:31:00 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 06:31:07 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 06:31:09 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 06:31:15 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 06:31:20 PM event=VOLTAGE NORMAL 121Vac temperature=69F
06/01/2009 07:53:49 PM event=VOLTAGE HIGH ALARM 123Vac temperature=69F
06/01/2009 07:53:58 PM event=VOLTAGE NORMAL 121Vac temperature=69F
06/01/2009 07:56:29 PM event=VOLTAGE HIGH ALARM 123Vac temperature=69F
06/01/2009 07:59:06 PM event=VOLTAGE NORMAL 121Vac temperature=69F
06/01/2009 07:59:12 PM event=VOLTAGE HIGH ALARM 123Vac temperature=69F
06/01/2009 07:59:30 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 07:59:56 PM event=VOLTAGE HIGH ALARM 123Vac temperature=69F
06/01/2009 08:00:00 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 08:00:09 PM event=VOLTAGE HIGH ALARM 123Vac temperature=69F
06/01/2009 08:00:10 PM event=VOLTAGE NORMAL 121Vac temperature=69F
06/01/2009 08:00:12 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 08:02:22 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 08:10:46 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 08:14:57 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 08:19:03 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 08:23:41 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 09:08:15 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 09:30:54 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 09:55:17 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 09:59:12 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:07:56 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:08:02 PM event=VOLTAGE NORMAL 120Vac temperature=70F
06/01/2009 10:51:40 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:52:02 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:55:21 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:55:31 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:55:51 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:56:00 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:56:38 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:58:10 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:58:11 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:58:47 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:58:52 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:59:02 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:59:06 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:59:20 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:59:23 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:59:28 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:59:32 PM event=VOLTAGE HIGH ALARM 123Vac temperature=70F
06/01/2009 10:59:34 PM event=VOLTAGE NORMAL 121Vac temperature=70F
06/01/2009 10:59:51 PM event=VOLTAGE HIGH ALARM 123Vac
 
ELA

ELA

Senior Member
Occupation
Electrical Test Engineer
Gar,
Based on the theory of amplitude modulation , my point is that there would have to be a 15Hz source in a very large magnitude (nearly equal to the carrier amplitude) in order to produce the side bands of the amplitude the OP stated.

I still believe that the readings reported are due to the the meter itself and not "real".

I went to the site provided by fields5491 but was unable to get the link for the manual to work.

I suspect Electrosmog :roll:
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
090606-1446 EST

ELA:

I also agree it would be a large percentage of modulation. Even though I suggested this as a possibility I do not think it is the source. It may well be a phantom created by the instrument.

My point of the reference was that the ratio of sidebands to carrier can be influenced by the amount of carrier that is removed.

15 Hz is a subharmonic of 45, 60, and 75. 45 and 75 have no harmonic relation to 60.

Since the 45 and 75 components diminish as the instrument is move away from the circuit, and I assume the 60 does as well, then we can assume it comes from the circuit electric field. Therefore, scope picture of 6 cycles should allow us to see any substantial modulation of the signal.

There has to be something very wrong in the basic waveform to generate large components at 45 and 75. I think it is an error introduced in the instrument.


fields5491:

I consider my supply voltage to be rather stable, and it varies more than your logged data.

I have four plots of it for short times shown at photos P22- P25 at
www.beta-a2.com/EE-photos.html.

This data is from 1 second samples. Voltage is quantizied to 0.1 V, and power to 10 W.

Your logged data has no correlation with a 15 Hz signal.

As ELA stated the modulation of 60 Hz probably needs to be large for you to see sideband components. Is your vertical scale log or linear? What is the design of the pickup element in your EMF instrument (transducer -- antenna -- capacitor)?

.
 
F

fields5491

Member
You continue to look at the instrument as faulty. Let's disregard this and look elsewhere.
I have not shared with you that a 'good source' has brought to my attention that 45 and 75 hz are both frequencies connected with submarine communications. It has been suggested that the Defense Department is connected with the matter and the home referenced has evidence of political targeting, long term.
Let me also suggest the following research articles be reviewed.
http://www.stetzerelectric.com/filters/research/

Apparently all of this is news to this forum.
 
catchtwentytwo

catchtwentytwo

Senior Member
fields5491 said:
You continue to look at the instrument as faulty. Let's disregard this and look elsewhere.
I have not shared with you that a 'good source' has brought to my attention that 45 and 75 hz are both frequencies connected with submarine communications. It has been suggested that the Defense Department is connected with the matter and the home referenced has evidence of political targeting, long term.
Let me also suggest the following research articles be reviewed.
http://www.stetzerelectric.com/filters/research/

Apparently all of this is news to this forum.
Click to expand...

Maybe not, see here
 
F

fields5491

Member
I took a quick look, apparently a lot of non-believers, I admit I didn't read all the posts.
My background is public health and now building biology. Look at the research, it is peer-reviewed. I know the filters work, at least they improve the environment.

I have no financial interest in the product, my only interest is public health.
I invite others interested in health effects of EMF to join a special interest group on EMF
http://healthandenvironment.org/working_groups/emf
There is no cost, ever.
 
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