Re: [PSES] Measurement Dilema - THE EXPLANATION!

[Doug Smith]

OK Everyone,  here is the explanation:

The box is superfluous, it just hides what is actually going on. The box 
contains two heavy gauge wires. One shorts the two tips sig and gnd together 
and the other connects the center point of the first wire  to the center pin of 
the BNC connector. This is equivalent to removing the box and putting a stiff 
wire into the BNC center pin  on the generator and connecting both probe tips 
and both ground leads to this stiff wire.

Doing so causes the generator to push a current out the prob e ground leads 
creating a voltage across the inductance of the leads that create a loop at the 
front of the probe. The current flowing through the ground leads creates 
magnetic fields that for the most part are captured by the loop formed by the 
ground leads and probe delivering the induced voltage to the probes.

The probes only respond to voltage between their tips and ground lead 
attachment point, and the ground lead induced voltage is delivered to each 
probe by loop they form.

Since the probes are lying apart from each other, one on the plastic table with 
a loop in its cable, and the other over a highly conducting (center layer) ESD 
mat, their common mode impedance will be different, varying at different 
frequencies. That results in different common mode currents on the probes and 
the ground lead induced voltages are therefore different and that is what is 
displayed on the scope. It is interesting that the current output of an HC240 
Octal Inverting Buffer can induce volts across the ground leads when its output 
is only 5 V P_P, but entirely understandable if you calculate e = Ldi/dt = 100 
nH*.040 A/2ns) as an approximation.

For the generator to push a current onto the probe cables, it must form an 
image current somewhere and that is displacement current to the nearby scope 
chassis and some radiation from the oscillator itself into the "ether," 
although it is on the small side to radiate itself efficiently at 40 MHz.

I suspect the total current being pushed onto the probes is about 40 mA, the 
short circuit current of the HC240 IC being used. At some frequencies, each 
probe cable will resonate with the capacitance back to the scope from the 
oscillator. By changing the frequency, I can make either probe register a 
larger signal than the other probe.

I love experiments like this. I have been doing this one for over 20 years for 
my classes and have have tons more demos to challenge engineering minds. Most 
of my demos have an unexpected result and the discussion that follows 
elucidates some engineering principle or addresses a myth.

Doug
University of Oxford, Course Tutor
Department for Continuing Education
Oxford, Oxfordshire, United Kingdom
--
Doug Smith
P.O. Box 60941
Boulder City, NV 89006-0941
TEL/FAX: 702-570-6108/570-6013
Mobile: 408-858-4528
Email: d...@dsmith.org
Web: http://www.dsmith.org
--



On Mon, 29 Jan 2018 14:40:17 -0800, "Tom Dagostino"  wrote:

Why is everybody looking for tricks or complex answers.  This is really a
very simple, basic issue.  If you look closely you will see the difference.

Tom Dagostino
971-279-5325
t...@teraspeedlabs.com 

Teraspeed Labs
 SW Wilshire Street
Suite 102
Portland, OR 97225


-Original Message-
From: si-list-bou...@freelists.org [mailto:si-list-bou...@freelists.org] On
Behalf Of Austin Mack
Sent: Monday, January 29, 2018 2:28 PM
To: d...@emcesd.com; 'si-list'
Subject: [SI-LIST] Re: ***UNCHECKED*** Measurement Dilema

Hi All,

It looks to me like the oscillator and its power pack (with very long leads)
are in close proximity to the CH2 probe cable. Since the oscillator output
is tied to GND at the probes, it and the floating power pack will be
radiating like crazy at 40MHz and electromagnetically and capacitively
coupling to the CH2 shield which BTW is close to a quarter wavelength.

Austin

-Original Message-
From: si-list-bou...@freelists.org [mailto:si-list-bou...@freelists.org] On
Behalf Of Doug Smith
Sent: Friday, January 26, 2018 2:53 PM
To: si-list 
Subject: [SI-LIST] ***UNCHECKED*** Measurement Dilema




Hi All,

Can you explain the result in this video I just made? Scope plots of the
same two nodes are completely different. Probes and scope are operating
normally, no problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY

I do a lot of experiments in my classes that give surprising results. Each
one addresses a design or troubleshooting problem that engineers do not
realize their troubleshooting efforts. Next
one:http://emcesd.com/bcsem_hfmeas.htm on March 13-16.

Doug

Re: [PSES] Measurement dilema

[Douglas Smith]

Not really. Full disclosure tomorrow when I get settled in the office. It is 
actually simpler than one might imagine, just will take me a fair amount of 
typing so need a real keyboard not an iPhone.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Sun, Jan 28, 2018 at 4:54, Bart De Geeter  wrote:
Hi Doug,



Could it be that there is just a piece of transmission line inside the box 
terminated with a certain impedance? You might be measuring in the middle of 
this transmission line.

If the input impedance selected on channel A of your oscilloscope is f.e 50 ohm 
and the other input channel has 1Mohm input impedance selected, you will 
measure a different voltage at this particular point (as the measured signal is 
the sum of the direct wave+ reflected wave on this transmission).



So far, my guess 



Greetings,

Bart



Van: Doug Smith [mailto:d...@emcesd.com]
Verzonden: vrijdag 26 januari 2018 23:50
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: [PSES] Measurement dilema



Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY [https://youtu.be/qj-HBFMEJiY]

Doug



-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
[http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] >
Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] >

For policy questions, send mail to:
Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
David Heald < dhe...@gmail.com [dhe...@gmail.com] >

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
[http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] >
Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] >

For policy questions, send mail to:
Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
David Heald < dhe...@gmail.com [dhe...@gmail.com] >

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Measurement dilema

[Douglas Smith]

I was thinking only that people who have had my course not reply because they 
should already know.
Will post the answer discussion later tomorrow. I have really enjoyed the 
replies and learned from them.
And you are right. Ground lead parasitic inductance plays a major part.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Sun, Jan 28, 2018 at 18:42, Ken Javor <ken.ja...@emccompliance.com> wrote:
Re: [PSES] Measurement dilema As long as we’re all chiming in here that was my 
guess as well (probe ground lead parasitics) but I thought the ground rule :-) 
was no group replies...

Ken Javor
Phone: (256) 650-5261






From: Dale Reid <re...@lexmark.com>
Reply-To: Dale Reid <re...@lexmark.com>
Date: Sun, 28 Jan 2018 20:38:56 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] Measurement dilema

How about the different size loops the ground leads on your probes are making.

Dale Reid
Product Safety Engineer
O +1 859 825 4733
re...@lexmark.com
<http://www.lexmark.com/> [http://www.lexmark.com/]
www.lexmark.com <http://www.lexmark.com> [http://www.lexmark.com]

On Sun, Jan 28, 2018 at 7:54 AM, Bart De Geeter <bart.de.gee...@telenet.be> 
wrote:
Hi Doug,

Could it be that there is just a piece of transmission line inside the box 
terminated with a certain impedance? You might be measuring in the middle of 
this transmission line.
If the input impedance selected on channel A of your oscilloscope is f.e 50 ohm 
and the other input channel has 1Mohm input impedance selected, you will 
measure a different voltage at this particular point (as the measured signal is 
the sum of the direct wave+ reflected wave on this transmission).

So far, my guess 

Greetings,
Bart


Van: Doug Smith [ mailto:d...@emcesd.com] [d...@emcesd.com]]
Verzonden: vrijdag 26 januari 2018 23:50
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: [PSES] Measurement dilema


Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY

Doug


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html 
[http://www.ieee-pses.org/list.html] (including how to unsubscribe) 
<http://www.ieee-pses.org/list.html> [http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher <j.bac...@ieee.org>
David Heald <dhe...@gmail.com>

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
emc-p...@ieee.org

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html 
[http://www.ieee-pses.org/list.html] (including how to unsubscribe) 
<http://www.ieee-pses.org/list.html> [http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas sdoug...@ieee.org
Mike Cantwell mcantw...@ieee.org

For policy questions, send mail to:
Jim Bacher j.bac...@ieee.org
David Heald dhe...@gmail.com

-


This message is from the IEEE Product

Re: [PSES] Measurement dilema

[Ken Javor]

As long as we’re all chiming in here that was my guess as well (probe ground
lead parasitics) but I thought the ground rule :-) was no group replies...

Ken Javor
Phone: (256) 650-5261




From: Dale Reid <re...@lexmark.com>
Reply-To: Dale Reid <re...@lexmark.com>
Date: Sun, 28 Jan 2018 20:38:56 -0500
To: <EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] Measurement dilema

How about the different size loops the ground leads on your probes are
making.     

Dale Reid
Product Safety Engineer
O  +1 859 825 4733
re...@lexmark.com
 <http://www.lexmark.com/>
www.lexmark.com <http://www.lexmark.com>

On Sun, Jan 28, 2018 at 7:54 AM, Bart De Geeter <bart.de.gee...@telenet.be>
wrote:
> Hi Doug,
>  
>    Could it be that there is just a piece of transmission line
> inside the box terminated with a certain impedance?  You might be measuring in
> the middle of this transmission line.
> If the input impedance selected on channel A of your oscilloscope is f.e  50
> ohm  and the other input channel has 1Mohm input impedance selected, you will
> measure a different voltage at this particular point (as the measured signal
> is the sum of the direct wave+ reflected wave on this transmission).
>  
> So far, my guess 
>  
> Greetings,
> Bart
>  
> 
> Van: Doug Smith [mailto:d...@emcesd.com]
> Verzonden: vrijdag 26 januari 2018 23:50
> Aan: EMC-PSTC@LISTSERV.IEEE.ORG
> Onderwerp: [PSES] Measurement dilema
>  
> 
> Hi All,
> 
> Can you explain the result in this video I just made? Scope plots of the same
> two nodes are completely different. Probes and scope are operating normally,
> no problem with the equipment itself.
> 
> If you have been to my seminars you know the answer, please do not post the
> answer unless you have not seen this experiment until now.
> 
> Hint 1: There are no EM fields radiating from the shielded box affecting the
> probes.
> Hint 2: There are no active components inside the box.
> 
> https://youtu.be/qj-HBFMEJiY
> 
> Doug 
> 
> 
> -
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> <emc-p...@ieee.org>
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
> 
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) <http://www.ieee-pses.org/list.html>
> List rules: http://www.ieee-pses.org/listrules.html
> 
> For help, send mail to the list administrators:
> Scott Douglas <sdoug...@ieee.org>
> Mike Cantwell <mcantw...@ieee.org>
> 
> For policy questions, send mail to:
> Jim Bacher <j.bac...@ieee.org>
> David Heald <dhe...@gmail.com>
> 
> -
> 
> 
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to
> emc-p...@ieee.org
> 
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
> 
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used
> formats), large files, etc.
> 
> Website:  http://www.ieee-pses.org/
> Instructions:  http://www.ieee-pses.org/list.html (including how to
> unsubscribe) <http://www.ieee-pses.org/list.html>
> List rules: http://www.ieee-pses.org/listrules.html
> 
> For help, send mail to the list administrators:
> Scott Douglas sdoug...@ieee.org
> Mike Cantwell mcantw...@ieee.org
> 
> For policy questions, send mail to:
> Jim Bacher  j.bac...@ieee.org
> David Heald dhe...@gmail.com

-


This message is from the IEEE Product Safety Engineering Society emc-pstc
discussion list. To post a message to the list, send your e-mail to
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at
http://product-compliance.oc.ieee.org/ can be used for graphics (in
well-used formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to
unsubscribe) <http://www.ieee-pses.org/list

Re: [PSES] Measurement dilema

[Dale Reid]

How about the different size loops the ground leads on your probes are
making.

*Dale Reid*
Product Safety Engineer
*O*  +1 859 825 4733
re...@lexmark.com

www.lexmark.com

On Sun, Jan 28, 2018 at 7:54 AM, Bart De Geeter 
wrote:

> Hi Doug,
>
>
>
>Could it be that there is just a piece of transmission line
> inside the box terminated with a certain impedance?  You might be measuring
> in the middle of this transmission line.
>
> If the input impedance selected on channel A of your oscilloscope is f.e
> 50 ohm  and the other input channel has 1Mohm input impedance selected, you
> will measure a different voltage at this particular point (as the measured
> signal is the sum of the direct wave+ reflected wave on this transmission).
>
>
>
> So far, my guess 
>
>
>
> Greetings,
>
> Bart
>
>
>
> *Van:* Doug Smith [mailto:d...@emcesd.com]
> *Verzonden:* vrijdag 26 januari 2018 23:50
> *Aan:* EMC-PSTC@LISTSERV.IEEE.ORG
> *Onderwerp:* [PSES] Measurement dilema
>
>
>
> Hi All,
>
> Can you explain the result in this video I just made? Scope plots of the
> same two nodes are completely different. Probes and scope are operating
> normally, no problem with the equipment itself.
>
> If you have been to my seminars you know the answer, please do not post
> the answer unless you have not seen this experiment until now.
>
> Hint 1: There are no EM fields radiating from the shielded box affecting
> the probes.
> Hint 2: There are no active components inside the box.
>
> https://youtu.be/qj-HBFMEJiY
>
> Doug
>
> -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to <
> emc-p...@ieee.org>
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in
> well-used formats), large files, etc.
>
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html
>
> For help, send mail to the list administrators:
> Scott Douglas 
> Mike Cantwell 
>
> For policy questions, send mail to:
> Jim Bacher 
> David Heald 
> -
> 
>
> This message is from the IEEE Product Safety Engineering Society emc-pstc
> discussion list. To post a message to the list, send your e-mail to 
> emc-p...@ieee.org
>
> All emc-pstc postings are archived and searchable on the web at:
> http://www.ieee-pses.org/emc-pstc.html
>
> Attachments are not permitted but the IEEE PSES Online Communities site at
> http://product-compliance.oc.ieee.org/ can be used for graphics (in
> well-used formats), large files, etc.
>
> Website: http://www.ieee-pses.org/
> Instructions: http://www.ieee-pses.org/list.html (including how to
> unsubscribe) 
> List rules: http://www.ieee-pses.org/listrules.html
>
> For help, send mail to the list administrators:
> Scott Douglas sdoug...@ieee.org
> Mike Cantwell mcantw...@ieee.org
>
> For policy questions, send mail to:
> Jim Bacher j.bac...@ieee.org
> David Heald dhe...@gmail.com
>

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Measurement dilema

[Brian O'Connell]

Pareto principle/distribution? Methinks it may be that way with all life 
sciences. After having read over 200 PhD and master's papers in 
agriculture/agronomy/botany, have come to the conclusion that their ilk's 
intellectual toolbox are simply not equipped with adequate mathematical tools, 
nor educational rigor. Agree that there is too much fiscal and political 
motivation in medical research, but to make a corollary, do not ascribe to mal 
intent what is incompetence. Or human 'entropy'.

As for the different signals, would have to know more about the analog front 
end to the scope and whether multiple channels share ADCs (have not read that 
model's manual). Had somewhat similar affects in my box where the mux and ADC 
were triggered by external events, not the microcontroller. Would need to see a 
frequency-domain of both channels to know if this is an artifact of 
'differential' sampling. Perhaps companding would do that, dunno. But probably 
just interference from space aliens.

Brian


From: John Woodgate [mailto:j...@woodjohn.uk] 
Sent: Saturday, January 27, 2018 11:44 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Measurement dilema

It's probably another case of the 80/20 rule. Even with peer-reviewed papers, 
the long-term opinion may be that 20% at most were of value.
John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK
On 2018-01-27 19:27, Douglas Smith wrote:
Great quote! It pretty much describes much of medical research in my opinion. 
The great thing about engineering is the field is “grounded” (pun intended) in 
fundamentals. No so much in medicine where money and politics matter as much as 
science. My hobby when I am not doing engineering is medicine and I read tons 
of medical studies. Many are either junk (poorly done) or fraud! Some are great.
Doug Smith
Sent from my iPhone
IPhone:  408-858-4528
Office:    702-570-6108
Email:     d...@dsmith.org
Website: http://dsmith.org

On Fri, Jan 26, 2018 at 17:34, Richard Nute <ri...@ieee.org> wrote:
 
Hi Doug:
 
While I don’t yet have the answer (and may never have the answer), I ran across 
this quote from Luigi Galvani which I think applies here:
 
“For it is easy in experimentation to be deceived, and to think one has seen 
and discovered what we desire to see and discover.”
 
Best regards,
Rich
 
 
From: Doug Smith [mailto:d...@emcesd.com] 
Sent: Friday, January 26, 2018 2:50 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Measurement dilema
 
Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY

Doug 

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
<emc-p...@ieee.org>

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas <sdoug...@ieee.org>
Mike Cantwell <mcantw...@ieee.org>

For policy questions, send mail to:
Jim Bacher:  <j.bac...@ieee.org>
David Heald: <dhe...@gmail.com>

Re: [PSES] Measurement dilema

[John Woodgate]

It's probably another case of the 80/20 rule. Even with peer-reviewed 
papers, the long-term opinion may be that 20% at most were of value.


John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2018-01-27 19:27, Douglas Smith wrote:
Great quote! It pretty much describes much of medical research in my 
opinion. The great thing about engineering is the field is “grounded” 
(pun intended) in fundamentals. No so much in medicine where money and 
politics matter as much as science. My hobby when I am not doing 
engineering is medicine and I read tons of medical studies. Many are 
either junk (poorly done) or fraud! Some are great.


Doug Smith
Sent from my iPhone
IPhone:  408-858-4528
Office:    702-570-6108
Email:     d...@dsmith.org
Website: http://dsmith.org

On Fri, Jan 26, 2018 at 17:34, Richard Nute  wrote:

Hi Doug:

While I don’t yet have the answer (and may never have the answer),
I ran across this quote from Luigi Galvani which I think applies here:

“For it is easy in experimentation to be deceived, and to think
one has seen and discovered what we desire to see and discover.”

Best regards,

Rich

*From:* Doug Smith [mailto:d...@emcesd.com]
*Sent:* Friday, January 26, 2018 2:50 PM
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* [PSES] Measurement dilema

Hi All,

Can you explain the result in this video I just made? Scope plots
of the same two nodes are completely different. Probes and scope
are operating normally, no problem with the equipment itself.

If you have been to my seminars you know the answer, please do not
post the answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box
affecting the probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY

Doug

-


This message is from the IEEE Product Safety Engineering Society
emc-pstc discussion list. To post a message to the list, send your
e-mail to >

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities
site at http://product-compliance.oc.ieee.org/ can be used for
graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to
unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas >
Mike Cantwell >

For policy questions, send mail to:
Jim Bacher >
David Heald >

-


This message is from the IEEE Product Safety Engineering Society
emc-pstc discussion list. To post a message to the list, send your
e-mail to >

All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities
site at http://product-compliance.oc.ieee.org/ can be used for
graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to
unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas >
Mike Cantwell >

For policy questions, send mail to:
Jim Bacher >
David Heald >

-


This message is from the IEEE Product Safety Engineering Society 
emc-pstc discussion list. To post a message to the list, send your 
e-mail to >


All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html


Attachments are not permitted but the IEEE PSES Online Communities 
site at http://product-compliance.oc.ieee.org/ can be used for 
graphics (in well-used formats), large files, etc.


Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to 
unsubscribe)

List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 

Re: [PSES] Measurement dilema

[Douglas Smith]

Great quote! It pretty much describes much of medical research in my opinion. 
The great thing about engineering is the field is “grounded” (pun intended) in 
fundamentals. No so much in medicine where money and politics matter as much as 
science. My hobby when I am not doing engineering is medicine and I read tons 
of medical studies. Many are either junk (poorly done) or fraud! Some are great.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Fri, Jan 26, 2018 at 17:34, Richard Nute  wrote:


Hi Doug:



While I don’t yet have the answer (and may never have the answer), I ran across 
this quote from Luigi Galvani which I think applies here:



“For it is easy in experimentation to be deceived, and to think one has seen 
and discovered what we desire to see and discover.”



Best regards,

Rich





From: Doug Smith [mailto:d...@emcesd.com]
Sent: Friday, January 26, 2018 2:50 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Measurement dilema



Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY [https://youtu.be/qj-HBFMEJiY]

Doug



-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
[http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] >
Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] >

For policy questions, send mail to:
Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
David Heald < dhe...@gmail.com [dhe...@gmail.com] >

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
[http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] >
Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] >

For policy questions, send mail to:
Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
David Heald < dhe...@gmail.com [dhe...@gmail.com] >

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Measurement dilema

[Douglas Smith]

That is certainly true, but the problem here is there is an error one is not 
aware of, although this is an extreme example.

Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: 
d...@dsmith.org Website: http://dsmith.org
On Fri, Jan 26, 2018 at 17:34, Richard Nute  wrote:


Hi Doug:



While I don’t yet have the answer (and may never have the answer), I ran across 
this quote from Luigi Galvani which I think applies here:



“For it is easy in experimentation to be deceived, and to think one has seen 
and discovered what we desire to see and discover.”



Best regards,

Rich





From: Doug Smith [mailto:d...@emcesd.com]
Sent: Friday, January 26, 2018 2:50 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Measurement dilema



Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY [https://youtu.be/qj-HBFMEJiY]

Doug



-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to < 
emc-p...@ieee.org [emc-p...@ieee.org] >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html [http://www.ieee-pses.org/emc-pstc.html]

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ [http://product-compliance.oc.ieee.org/] 
can be used for graphics (in well-used formats), large files, etc.

Website: http://www.ieee-pses.org/ [http://www.ieee-pses.org/]
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
[http://www.ieee-pses.org/list.html]
List rules: http://www.ieee-pses.org/listrules.html 
[http://www.ieee-pses.org/listrules.html]

For help, send mail to the list administrators:
Scott Douglas < sdoug...@ieee.org [sdoug...@ieee.org] >
Mike Cantwell < mcantw...@ieee.org [mcantw...@ieee.org] >

For policy questions, send mail to:
Jim Bacher < j.bac...@ieee.org [j.bac...@ieee.org] >
David Heald < dhe...@gmail.com [dhe...@gmail.com] >

-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: 

Re: [PSES] Measurement dilema

[Richard Nute]

 

Hi Doug:

 

While I don’t yet have the answer (and may never have the answer), I ran across 
this quote from Luigi Galvani which I think applies here:

 

“For it is easy in experimentation to be deceived, and to think one has seen 
and discovered what we desire to see and discover.”

 

Best regards,

Rich

 

 

From: Doug Smith [mailto:d...@emcesd.com] 
Sent: Friday, January 26, 2018 2:50 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Measurement dilema

 

Hi All,

Can you explain the result in this video I just made? Scope plots of the same 
two nodes are completely different. Probes and scope are operating normally, no 
problem with the equipment itself.

If you have been to my seminars you know the answer, please do not post the 
answer unless you have not seen this experiment until now.

Hint 1: There are no EM fields radiating from the shielded box affecting the 
probes.
Hint 2: There are no active components inside the box.

https://youtu.be/qj-HBFMEJiY

Doug 

  

 

-


This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 
 >

All emc-pstc postings are archived and searchable on the web at: 
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website: http://www.ieee-pses.org/
Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) 
 
List rules: http://www.ieee-pses.org/listrules.html 

For help, send mail to the list administrators:
Scott Douglas  >
Mike Cantwell  > 

For policy questions, send mail to:
Jim Bacher  >
David Heald  > 


-

This message is from the IEEE Product Safety Engineering Society emc-pstc 
discussion list. To post a message to the list, send your e-mail to 


All emc-pstc postings are archived and searchable on the web at:
http://www.ieee-pses.org/emc-pstc.html

Attachments are not permitted but the IEEE PSES Online Communities site at 
http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used 
formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://www.ieee-pses.org/list.html (including how to unsubscribe)
List rules: http://www.ieee-pses.org/listrules.html

For help, send mail to the list administrators:
Scott Douglas 
Mike Cantwell 

For policy questions, send mail to:
Jim Bacher:  
David Heald: