On second thought EMC consultant Ghery Pettit is an excellent better
starting point.
https://pettitemcconsulting.com/
Ghery has been directly involved with the design and build of several EMC
test sites including a 30 meter OATS.
Regards,
Manny
On Wed, Mar 10, 2021 at 11:11 AM Manny Barron
Hi Mark,
ETS-Lindgren is a good starting point:
http://www.ets-lindgren.com/
Also here's an interesting helpful article:
https://incompliancemag.com/article/lessons-learned-from-the-design-and-construction-of-an-open-area-test-site-oats-and-sound-measurement-building/
There are important
, Product Safety/EMC
Ortho Clinical Diagnostics
[cid:image001.png@01D715AB.EF9C0750]
From: Dan Roman <0d75e04ed751-dmarc-requ...@listserv.ieee.org>
Sent: Wednesday, March 10, 2021 11:59 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS installation
EXTERNAL SENDER: Verify
: [PSES] OATS installation
Hello,
In an effort to get more accurate pre-compliance measurements, were looking
into building an OATS setup. Does anyone know of any companies in the US
that will install/build one?
Thanks,
Mark Stultz
10175 Philipp Parkway
Senior Mechanical
Hello,
In an effort to get more accurate pre-compliance measurements, we're looking
into building an OATS setup. Does anyone know of any companies in the US that
will install/build one?
Thanks,
Mark Stultz
10175 Philipp Parkway
Senior Mechanical Development Engineer
Streetsboro, OH 44241
Very helpful, thanks Brent!
From: Brent DeWitt [mailto:bdew...@ix.netcom.com]
Sent: 08 August 2015 01:19
To: Pawson, James; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] Calculating Reflection Angles on OATS/SAC
Hi James,
The image concept again is useful. By definition, the ground reference
@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Calculating Reflection Angles on OATS/SAC
Very helpful, thanks Brent!
From: Brent DeWitt [mailto:bdew...@ix.netcom.com]
Sent: 08 August 2015 01:19
To: Pawson, James; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: [PSES] Calculating Reflection Angles on OATS/SAC
: Pawson, James [mailto:james.paw...@echostar.com]
Sent: Thursday, August 06, 2015 5:13 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Calculating Reflection Angles on OATS/SAC
Many thanks for all of the replies on this topic. The conceptual key I
lacked was the image of the receiver
@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Calculating Reflection Angles on OATS/SAC
Many thanks for all of the replies on this topic. The conceptual key I lacked
was the image of the receiver below the ground plane which made the
calculations a lot simpler and I've now got an up and running
In message FCA549BE3ECF9D4CB8CB8576837EA48920AECF@ZEUS.cetest.local,
dated Thu, 6 Aug 2015, ce-test, qualified testing bv - Gert Gremmen
g.grem...@cetest.nl writes:
Yes, you may (at your choice) add or subtract 180 degrees for the
reflected vertically polarised wave only!
..or add a half
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Calculating Reflection Angles on OATS/SAC
Hi,
I'm trying to calculate the distances/angles at which a maximum (in phase) or
minimum (anti-phase) signal would occur on an OATS/SAC.
I can do this simply when the TX and RX antennae are the same height above
:
07/31/2015 08:17 AM
Subject:
[PSES] Calculating Reflection Angles on OATS/SAC
Hi,
I’m trying to calculate the distances/angles at which a maximum (in phase)
or minimum (anti-phase) signal would occur on an OATS/SAC.
I can do this simply when the TX and RX antennae are the same height above
In message 002b01d0cd7c$e1128330$a3378990$@integrity.com, dated Sun, 2
Aug 2015, Manny Barron mbar...@integrity.com writes:
Back in 1998 when I wrote a paper for the IEEE EMC Symposium on
calculating the ?Theoretical Normalized Site Attenuation (NSA) by
Spreadsheet Analysis?, I needed to do a
) or minimum (anti-phase) signal would occur on an OATS/SAC.
Apologies all round. I just didn't take in that first paragraph.
--
OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk
When I turn my back on the sun, it's to look for a rainbow
John Woodgate, J M Woodgate and Associates, Rayleigh
To: 'EMC-PSTC@LISTSERV.IEEE.ORG'
Cc: 'Pawson, James'; 'John Woodgate'; 'ce-test, qualified testing bv - Gert
Gremmen'; 'Heckrotte, Michael'; 'CR'; 'Brent DeWitt'; 'T.Sato'
Subject: RE: [PSES] Calculating Reflection Angles on OATS/SAC
Hi James,
Back in 1998 when I wrote a paper for the IEEE EMC
On 7/31/2015 10:59 AM, Pawson, James wrote:
I can do this simply when the TX and RX antennae are the same height
above the reflecting surface as the point of reflection lies halfway
between the two antennae, Distance_tx = Distance_rx. The direct and
reflected paths can be calculated using
In message 51qlfiadg5uvf...@jmwa.demon.co.uk, dated Fri, 31 Jul 2015,
John Woodgate j...@jmwa.demon.co.uk writes:
Is there a standard equation for calculating the reflection angle on
an OATS/SAC with a varying height antenna? Or can someone give me some
pointers to help me figure it out
[mailto:j...@jmwa.demon.co.uk]
Sent: Friday, July 31, 2015 2:34 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Calculating Reflection Angles on OATS/SAC
In message
dm2pr04mb8955244ee213552f09d187498...@dm2pr04mb895.namprd04.prod.outlook
.com, dated Fri, 31 Jul 2015, Heckrotte, Michael
Reflection Angles on OATS/SAC
On 7/31/2015 10:59 AM, Pawson, James wrote:
I can do this simply when the TX and RX antennae are the same height
above the reflecting surface as the point of reflection lies halfway
between the two antennae, Distance_tx = Distance_rx. The direct and
reflected
a valid topic but the original enquirer didn't ask about it.
Actually, he did, in his first paragraph:
I'm trying to calculate the distances/angles at which a maximum (in phase) or
minimum (anti-phase) signal would occur on an OATS/SAC
In message
dm2pr04mb895279e532e2efe5d2d034d98...@dm2pr04mb895.namprd04.prod.outlook
.com, dated Sat, 1 Aug 2015, Heckrotte, Michael
michael.heckro...@ul.com writes:
Things can get more interesting at the step of determining the Rx
heights at which the maximum (in-phase) and minimum
On Fri, 31 Jul 2015 14:59:27 +,
Pawson, James james.paw...@echostar.com wrote:
I'm trying to calculate the distances/angles at which a maximum (in phase) or
minimum (anti-phase) signal would occur on an OATS/SAC.
...
Is there a standard equation for calculating the reflection angle
Hi,
I'm trying to calculate the distances/angles at which a maximum (in phase) or
minimum (anti-phase) signal would occur on an OATS/SAC.
I can do this simply when the TX and RX antennae are the same height above the
reflecting surface as the point of reflection lies halfway between the two
In message
cec6039c09630543852b1a8cfa0a0c790ea7f...@chwpiexc10.sats.corp, dated
Fri, 31 Jul 2015, Pawson, James james.paw...@echostar.com writes:
Is there a standard equation for calculating the reflection angle on an
OATS/SAC with a varying height antenna? Or can someone give me some
note that conclusions drawn (and they are spectacular) about the
functioning of the OATS are correct but applicable
to a infinitely small radiate/receive antenna only. For larger antenna
one might need to integrate over the size of both the antennas.
Gert Gremmen
Van: Pawson, James
-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Calculating Reflection Angles on OATS/SAC
Note that vertical waves invert in polarity on reflection with the ground
plane, where horizontal polarized waves do not.
I remember that calculations were much easier when the send antenna is seen as
if it were
In message FCA549BE3ECF9D4CB8CB8576837EA48920AEBD@ZEUS.cetest.local,
dated Fri, 31 Jul 2015, ce-test, qualified testing bv - Gert Gremmen
g.grem...@cetest.nl writes:
I remember that calculations were much easier when the send antenna is
seen as if it were under the ground plane for the
In message
dm2pr04mb8955244ee213552f09d187498...@dm2pr04mb895.namprd04.prod.outlook
.com, dated Fri, 31 Jul 2015, Heckrotte, Michael
michael.heckro...@ul.com writes:
Perhaps someone with a postgraduate degree in mathematics could derive
an analytical formula, but as an engineer I used
Worldly Experts,
I am looking for recommendations/experiences relating to list based radiated
emissions measurement software. This will be used in an OATS environment
where trace based software does not work well due to ambient signals. I will
be driving either a RS or Keysight (aka
, August 05, 2014 7:32 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] EMI measurement software in OATS environment
Worldly Experts,
I am looking for recommendations/experiences relating to list based radiated
emissions measurement software. This will be used in an OATS environment
where trace
:36 PM
Aan: EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: [PSES] Would in situ testing be considered OATS FAR SAC TEM
or other?
In a previous thread I noted EN 61000-6-4:2007 now had A1:2011 as the
cited reference for EMCD presumption of conformity. I was trying to
understand if this absolutely meant
analysis on A1, among a few other small changes, the big
change is in the test requirements for the enclosure port.
Recalling
FAR = Full Anechoic Room
OATS = Open Area Test Sight
SAC = Semi-Anechoic Chamber
TEM = Transvers Electromagnetic Mode
Prior to A1, the spec was for OATS or SAC test sites
Thanks for all the feedback, I shall follow up on the information kindly
provided.
I particulary enjoyed some of the stories.
Regards,
James
From: Pawson, James
Sent: 16 October 2012 15:27
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] OATS vs FAR Radiated
guys sure like your OATS! (;-)
--
OOO - Own Opinions Only. See www.jmwa.demon.co.uk
The longer it takes to make a point, the more obtuse it proves to be.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK
-
This message
Distance m:
10, Measurement Detector type/bandwidth: Quasi Peak/120 kHz, Class B limits
dB(uV/m) *OATS/SAC* (see Table A.1): 30
Table clause: A4.1, Frequency range MHz: 230 - 1 000, Measurement Distance
m: 10, Measurement Detector type/bandwidth: Quasi Peak/120 kHz, Class B
limits dB(uV/m) *OATS/SAC
And has any of this OATS, SAR, FAR, and TEM cell data differences been
correlated to actual interference problems? Is the EMC industry crying
wolf?
Limits and test methods should be based in reality. They should not be
academic exercises. For example, much of the world's products
In message
of583e7385.c0c56cf9-on86257a9a.0040152b-86257a9a.00418...@mmm.com,
dated Wed, 17 Oct 2012, rehel...@mmm.com writes:
And has any of this OATS, SAR, FAR, and TEM cell data differences been
correlated to actual interference problems? Is the EMC industry crying
wolf?
The only
. Measuring
distance was determined in a similar fashion, 3 meters being the home
environment, and 10 meters being the work or non-home environment.
I vaguely recall a 30 meter distance. All this are tales of the dark side when
there were only OATS and testing was all day long in the blistering summer
antenna-test sample separation, but also the specific type
of electric field probe or antenna used in each frequency band.
Ken Javor
Phone: (256) 650-5261
From: rehel...@mmm.com
Date: Wed, 17 Oct 2012 06:56:03 -0500
To: emc-p...@ieee.org
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
...@ieee.org] On Behalf Of Ken Javor
Sent: Wednesday, October 17, 2012 9:45 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
What is arbitrary and capricious about setting EMI limits just below a level
that provides a minimum quality standard?
Ken Javor
LOUD and interfered with everything. The limits we have today fixed the
problem.
Ghery S. Pettit
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken Javor
Sent: Wednesday, October 17, 2012 9:45 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated
, EMC-PSTC@LISTSERV.IEEE.ORG
EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
Way back in the old days, so goes the tale as it was told to me, for the
FCC,broadcast receivers were determined to have a certain level of
sensitivity for reliable reception
, and
delete it from your computer system.
From: Thomas Cokenias [mailto:t...@tncokenias.org]
Sent: Wednesday, October 17, 2012 10:06 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
When I worked at FCC I remember being told the interference limits
...@intel.com]
Sent: Wednesday, October 17, 2012 9:54 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
The 30 meter limits existed in a German standard and Edition 1 of CISPR 22.
Edition 2 made Class A and Class B limits at the same distance, 10 meters
Javor ken.ja...@emccompliance.com, EMC-PSTC@LISTSERV.IEEE.ORG
EMC-PSTC@LISTSERV.IEEE.ORG
cc
Subject
RE: [PSES] OATS vs FAR Radiated Emissions Limits
The 30 meter limits existed in a German standard and Edition 1 of CISPR
22. Edition 2 made Class A and Class B limits at the same distance
In message cca44ad4.2f74e%ken.ja...@emccompliance.com, dated Wed, 17
Oct 2012, Ken Javor ken.ja...@emccompliance.com writes:
What is arbitrary and capricious about setting EMI limits just below a
level that provides a minimum quality standard?
I suspect it's the assumption about receiver
In message
63e38a5b081437478c77651f3d56c64f2517f...@orsmsx102.amr.corp.intel.com,
dated Wed, 17 Oct 2012, Pettit, Ghery ghery.pet...@intel.com writes:
And, why did we have the limits? Because early home computers were
LOUD and interfered with everything. The limits we have today fixed
the
In message cca44bd5.2f750%ken.ja...@emccompliance.com, dated Wed, 17
Oct 2012, Ken Javor ken.ja...@emccompliance.com writes:
There are indeed near field test methods. They are enshrined in
vehicle-based standards, such as MIL-STD-461, DEF-STAN-5941,
RTCA/DO-160 and its EUROCAE equivalent, and
Of John Woodgate
Sent: Wednesday, October 17, 2012 10:59 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
In message
63e38a5b081437478c77651f3d56c64f2517f...@orsmsx102.amr.corp.intel.com,
dated Wed, 17 Oct 2012, Pettit, Ghery ghery.pet...@intel.com writes
In message
63e38a5b081437478c77651f3d56c64f2517f...@orsmsx102.amr.corp.intel.com,
dated Wed, 17 Oct 2012, Pettit, Ghery ghery.pet...@intel.com writes:
No limits in the US until the home computer came along and caused
massive hate and discontent. Prior to that it was primarily the
Germans
0871/6.78) that worried about this matter.
Ghery S. Pettit
-Original Message-
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of John Woodgate
Sent: Wednesday, October 17, 2012 10:59 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated
Cc: John Woodgate; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
The US had limits on other unintentional radiators since at least the 50s: low
power AM transmitters, TV and radio receiver oscillators, garage door openers
For a long time (I think since
: Re: [PSES] OATS vs FAR Radiated Emissions Limits
In message cca44bd5.2f750%ken.ja...@emccompliance.com, dated Wed, 17
Oct 2012, Ken Javor ken.ja...@emccompliance.com writes:
There are indeed near field test methods. They are enshrined in
vehicle-based standards, such as MIL-STD-461, DEF-STAN
circa 1977 was the basis for USA EMI limits in Title 47 CFR Part 15.
Ken Javor
Phone: (256) 650-5261
From: John Woodgate j...@jmwa.demon.co.uk
Date: Wed, 17 Oct 2012 18:59:04 +0100
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
In message
[mailto:ken.ja...@emccompliance.com]
Sent: Wednesday, October 17, 2012 12:34 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
EMI limits for radio frequency receivers and transmitters date back to the
creation of the FCC in the USA and the 1930s as Mr
We've just received EN 61000-6-3:2007 + A1:2011 which has added the ability to
test radiated emissions in either an OATS, Fully Anechoic Room (FAR) or TEM
waveguide.
What puzzled me is the limits for the FAR @ 3m:
30MHz ~ 230MHz: 42 to 35dBuV decreasing linearly with the log
]
Sent: 16 October 2012 15:27
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] OATS vs FAR Radiated Emissions Limits
We've just received EN 61000-6-3:2007 + A1:2011 which has added the ability to
test radiated emissions in either an OATS, Fully Anechoic Room (FAR) or TEM
waveguide.
What puzzled me
In message
a60ff8a65589d24a98d82fafc6f0ac56062eb8c...@euroexcc1.sats.corp, dated
Tue, 16 Oct 2012, Pawson, James james.paw...@echostar.com writes:
These limits are lower than those for an OATS at 3m. Does anyone know
why the limits are lower and of a different characteristic? I'm
guessing
| Solar Business | CANADA |
Regulatory Compliance Engineering
From:
John Woodgate j...@jmwa.demon.co.uk
To:
EMC-PSTC@LISTSERV.IEEE.ORG
Date:
10/16/2012 09:40 AM
Subject:
Re: [PSES] OATS vs FAR Radiated Emissions Limits
In message
a60ff8a65589d24a98d82fafc6f0ac56062eb8c...@euroexcc1
In message
OFDEF1DD24.6EF50883-ON88257A99.005ECCE0-88257A99.005FC1FD@US.Schneider-E
lectric.com, dated Tue, 16 Oct 2012,
ralph.mcdiar...@schneider-electric.com writes:
I've read that, depending on antenna size, 3 metre distance is within
what is called the near field and if so, then I assume
Several years ago I was using a 3m FAR for pre-compliance measurements.
They were using a giant BiLog antenna for the measurements. A constant
factor was added to the measured values to arrive at the OATS value. The
reason I stopped using their facility was because the data didn't
correlate
was added to the measured values to arrive at the OATS value.
The reason I stopped using their facility was because the data didn't
correlate well with the 10m semi-anechoic chamber.
This sort of thing will continue, but we may hope that it doesn't create
an insuperable problem, because the correct
With Experience Ltd.
W. London, UK
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of
ravinder.ajm...@hgst.com
Sent: 16 October 2012 19:44
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] OATS vs FAR Radiated Emissions Limits
Several years ago I was using a 3m FAR for pre-compliance
...@hgst.com,
dated Tue, 16 Oct 2012, ravinder.ajm...@hgst.com writes:
Several years ago I was using a 3m FAR for pre-compliance
measurements. They were using a giant BiLog antenna for the
measurements. A constant factor was added to the measured values to
arrive at the OATS value. The reason I
There are two reasons I am aware of.
The lack of a 6 dB reflection (which is slightly less due to way
length),
requires a 5 dB lower limit (thus the 35 instead of 40 at 230 MHz).
Why then is this 35 not used at 30 MHz?
The fact that a FAR/OATS has a problem in achieving an optimal
summation
to the originator
From: Charlie Blackham [mailto:emcp...@sulisconsultants.com]
Sent: 28 February 2011 17:04
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] plastic building for OATS
Group
Has anyone recently installed a plastic OATS building ? (That’s
Group
Has anyone recently installed a plastic OATS building ? (That’s the Open
Area Test Site variety rather than a grain storeJ )
Looking at doing something with a client and we are interested in any
suppliers anyone can recommend – UK/EU based preferred – size approx 3m x
5m x 3m high
It’s worse than just the filter. How long are the wire runs from the
outlets on the turntable to the filter? What is between the filter and the
outlets? Circuit breaker panels in the turntable pit? Or not? How are the
wires run? Different ways for different OATS facilities, not just between
Date: 02/13/2011 06:07 AM
Subject:Re: [PSES] OATS vs anechoic
HI Brian,
a number of things can be going on. Just for a start, the chambers and OATS
have NSA done, if your problems are vertical, it's possible to have 8 dB
difference in NSA especially
chamber data indicates from +5dB to +11dB in several
frequencies; while the 10m OATS says the unit passes Class B, min -4.2dB.
Huh?!? What is the physics behind the difference between an outside site and
absorbers? Where are the Borg when you need them?
Brian
/13/11, Derek Walton lfresea...@aol.com wrote:
From: Derek Walton lfresea...@aol.com
Subject: Re: [PSES] OATS vs anechoic
To: oconne...@tamuracorp.com, bdew...@ix.netcom.com
Cc: EMC-PSTC@LISTSERV.IEEE.ORG
Date: Sunday, February 13, 2011, 9:04 AM
HI Brian,
a number of things can be going on. Just for a start, the chambers and OATS
have NSA done, if your problems are vertical, it's possible to have 8 dB
difference in NSA especially at the lower end: just keep that in mind.
HOWEVER, NSA doesn't always reflect what the EUT does on the site
:
From: Brian O'Connell oconne...@tamuracorp.com
Subject: RE: OATS vs anechoic
To: EMC-PSTC@LISTSERV.IEEE.ORG
Date: Saturday, February 12, 2011, 6:22 PM
Just finished 2d OATS site - was not
able to detect much of anything.
Went back to indoors fully anechoic, where the noise plot
cord radiator makes a little more sense to me, I
think...
Brian
-Original Message-
From: Brent G DeWitt
Sent: Saturday, February 12, 2011 3:53 PM
To: oconne...@tamuracorp.com
Subject: RE: [PSES] OATS vs anechoic
Hi again Brian,
How is the power cord dressed
Just finished 2d OATS site - was not able to detect much of anything.
Went back to indoors fully anechoic, where the noise plot is deafening.
This is a simple 100W unit with one main ac/dc converter and (6) dc current
modulators. Construction is mostly plastic, with exception of metal base
plate
In message 001101cbcaf2$de4f81c0$d600a...@tamuracorp.com, dated Sat,
12 Feb 2011, Brian O'Connell oconne...@tamuracorp.com writes:
The 10m fully anechoic chamber data indicates from +5dB to +11dB in
several frequencies; while the 10m OATS says the unit passes Class B,
min -4.2dB.
Huh?!? What
Brian,
Is it as simple as your signals that are failing in the chamber are
hidden under ambient on the OATS? Same frequencies? What frequencies (eg
signals in the 30 to 200 MHz range)?
All the absorber is suppose to do is make the metal walls and the
ceiling transparent from 30
Good People,
Have tested at several sites. All are 'big' names and have a good reputation.
The 10m fully anechoic chamber data indicates from +5dB to +11dB in several
frequencies; while the 10m OATS says the unit passes Class B, min -4.2dB.
Huh?!? What is the physics behind the difference
In message 5744AE50340EDA49A436A35B99FB2753152884@S1.DLSEMC.local,
dated Tue, 29 Sep 2009, Bill Stumpf bstu...@dlsemc.com writes:
From experience, galvanized metal sheet works pretty well but is
difficult to weld or solder.
Yes. Welding is compromised by the zinc coating, which oxidizes and
Has anyone tried conductive coatings/paints as a ground plane for a
weather-protected OATS? I can see many reasons why this might be problematic,
but I am toying around with different ideas. From experience, galvanized metal
sheet works pretty well but is difficult to weld or solder.
Thanks
frequency
measured.
Having an EUT with larger dimensions, cables etc. increases the directivity at
the upper end of
the frequency range and a lack of precision in cable positioning leads to
larger variations
in the lower frequency band. All this leads to larger differences between GTEM
and OATS when
There have been inputs saying that GTEM results cannot possibly correlate
with far field OATS measurements, but I disagree, based on personal
experience with a customer who hired me to make that very thing happen for
him.
My customer needed to qualify desktop devices, and they had bought quite
In message 380-22009753182929...@earthlink.net, dated Fri, 3 Jul 2009,
Cortland Richmond k...@earthlink.net writes:
I was there for a little over three tears
I'm sure you meant that!
--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
Things can always get better. But
between an OATS and our chamber. I was there for a little
over three tears and after we adjusted the limit lines we got pretty good
results. At least, if we said something was going to be over, it WAS over.
But that was comparing apples to crabapples. Comparing the GTEM and the TEM
cells
In message
bd0371bcc07a3b4d88d6cd2fcf17ae5905e83...@ntxboimbx22.micron.com, dated
Fri, 3 Jul 2009, codymil...@micron.com writes:
I am trying to understand how to properly use TEM and GTEM cells to
take radiated emissions data. Has anyone had any success in correlating
far field radiated
I am trying to understand how to properly use TEM and GTEM cells to take
radiated emissions data. Has anyone had any success in correlating far
field radiated emissions measurements with GTEM measurements?
Thanks,
Cody
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This message is from the IEEE Product Safety Engineering Society emc-pstc
In message 002301c9bd96$bd225e20$37671a60$@dk, dated Wed, 15 Apr 2009,
Kim Boll Jensen k...@bolls.dk writes:
We do something like this, and just state in the report that all
emission over the limited have been verified to be background be
switching off the EUT.
That is OK if the emission is
Fra: emc-p...@ieee.org [mailto:emc-p...@ieee.org] På vegne af Derek Walton
Sendt: 14. april 2009 22:31
Til: codymil...@micron.com
Cc: emc-p...@ieee.org
Emne: Re: Radiated Emission Reports when using an OATS
HI Cody,
we perform pre-scan and the do final measurements on an OATS. In the
body
HI Cody,
we perform pre-scan and the do final measurements on an OATS. In the
body of the test report I address our process. I also give the reader
confidence that we know what were doing on an OATS by citing some of the
techniques we use to discriminate signals from interference.
The report
...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of
codymil...@micron.com
Sent: Thursday, October 16, 2008 5:56 PM
To: emc-p...@ieee.org
Subject: OATs enclosure interference
Hi all,
We are in the process of building an OATS and we have a building/enclosure
that is made of fiberglass. A link
Hi all,
We are in the process of building an OATS and we have a building/enclosure
that is made of fiberglass. A link to the enclosure link can be seen below. My
question is does the door opening to the dome need to be facing the antenna
mast while tests are running so
Cody,
Many years ago I did an NSA measurement on an OATS that had a (large
room-size, not tent-size) rectangular fiberglass enclosure over the turntable.
There was a personnel door between the turntable and the antenna. With this
door open, the difference in dielectric constant between
Of Michael
Heckrotte
Sent: Thursday, October 16, 2008 3:31 PM
To: codymil...@micron.com; emc-p...@ieee.org
Cc: emcp...@aol.com; emc-p...@ieee.org
Subject: RE: OATs enclosure interference
Cody,
Many years ago I did an NSA measurement on an OATS that had a (large
room-size, not tent-size
Hello Colleagues
After rain on an OATS, what are your typical guidelines for the resumption of
test?
I worked with one great engineer on this board at one time who had seen
dramatic differences on his OATS after rain and would shut down until the next
day when the site was dry.
We
Mac,
I have witnessed significant variations in measurements depending on if the
OATS was wet or not. It was several dB, and that amount varied a lot over the
frequency range. Additionally, IIRC the way it varied over frequency was also
not particularly constant rain storm to rain storm. I
Bill,
They were sheet steel, I think about 4mm thick and were continuously welded.
The other thing I forgot to mention was that it was blindingly bright to be on
the OATS in full sunshine.
Luke
Bill Owsley wdows...@yahoo.com 27 February 2008 16:20
We put a brilliant white tent over
We put a brilliant white tent over the whole OATS and ground plane for a
little environment consideration for the humans that had to attend to the
gear. And still had big problems. How were the plates attached together for
your OATS?
Luke Turnbull luke.turnb...@trw.com wrote:
Cody,
If going
Cody,
If going for the sheet metal, paint it brilliant white, and you won't have any
significant issues with expansion. We had and OATS that was painted white,
but we also had some stainless steel hatch covers. On a sunny day, the
stainless steel was too hot to touch, but the groundplane
, thermal gloves, face shield, gas mask
for the toxic fumes, practice a little, then hire someone to take on the job.
Good Luck,
- Bill
codymil...@micron.com wrote:
Any recommendations on material to use for the ground plane of an OATS.
I am also interested in methods for connecting sheets
Any recommendations on material to use for the ground plane of an OATS.
I am also interested in methods for connecting sheets together if sheet
metal was used. I have some concerns with expansion due to temperature
change.
Thanks,
Cody
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