Hi Jim,
As a basic test you can make an RJ45 connector that connects the EUT TX lines
to the RX lines thus looping back the Ethernet interface onto itself. This
certainly works for 100BaseTX because the EUT sees it's own Link Test Pulse,
assumes it is connected to another Ethernet interface
. Not quite what you were asking for though :(
Regards,
James
From: Chris Wells [mailto:radioactive55...@comcast.net]
Sent: 28 December 2011 17:03
To: Pawson, James; 'Knighten, Jim L'; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: What means do you use to exercise Ethernet
) chasgra...@gmail.commailto:chasgra...@gmail.com
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Pawson, James
Sent: Thursday, December 29, 2011 2:55 AM
To: 'Chris Wells'; 'Knighten, Jim L'; EMC-PSTC@LISTSERV.IEEE.ORG
Subject: RE: What means do you use to exercise Ethernet telecom ports
Hello list members,
We are wanting to test one of our products, which contains a WiFi interface, in
our anechoic chamber. To ensure the WiFi is active we would need to set up
antennae in the anechoic chamber itself - the irony of introducing radio into a
radio-quiet environment is not lost on
Thank you to all who responded with some very practical hints and tips. As
recommended by several people I'm keeping the AP outside of the chamber and
putting some SMA connectors through the bulkhead to attach the antennas.
Many thanks
James
From: Pawson
Hi folks,
We are looking at the possibility of expanding our test facilities with a
screened room. This would be
Does anyone know of any surplus screened rooms for sale in the United Kingdom /
Western Europe area?
Alternately, does anyone have any tips for building one? Obvious problem is
Bit of a regulatory puzzler here, please bear with me.
Testing an intentional radiator to FCC 15.247. Spurious emissions allowed to be
-20 dBc except in the 15.205 restricted bands where the general radiated
emissions limits in 15.209.
Radiated emissions limits: 216 ~ 960 MHz = 200 uV/m, 960
.
Thanks
James
From: Grace Lin [mailto:graceli...@gmail.com]
Sent: 15 February 2012 12:42
To: Pawson, James
Cc: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: FCC - Intentional Radiators, Restricted Bands and 960 MHz
James,
FCC published a new DTS procedure, FCC KDB
=
From:Pawson, James james.paw...@echostar.com
To:'Grace Lin' graceli...@gmail.com
Cc:EMC-PSTC@LISTSERV.IEEE.ORG EMC-PSTC@LISTSERV.IEEE.ORG
Date:02/15/2012 07:03 AM
Subject:RE: FCC - Intentional Radiators, Restricted Bands and 960 MHz
Sent by:emc-p
Currently only available as a USB adaptor for charging phones/MP3 players/etc
with
http://themu.co.uk/
From: Pettit, Ghery [mailto:ghery.pet...@intel.com]
Sent: 21 February 2012 16:03
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] British plug gets a
Hi Ed,
I've been making antenna pattern measurements recently in our chamber and I too
see a variation as you described. One theory I'm working on is that our
turntable might not be as accurate in it's 5º increments as it could be. If the
set point has a tolerance of 1-2º and that lies on the
Hopefully their compliance guy is having a straightforward time of things!
http://www.reghardware.com/2012/03/29/raspberry_pi_supplier_apologises_for_ship_date_delay_glitch/
http://www.raspberrypi.org/archives/852
Worth reading the last link for some of the commentards :P
James Pawson
Hello,
I can't find any clauses in 61000-4-3 (radiated RF immunity) that deal with the
rate of application of the RF field.
My understanding is that the test is generally performed by setting the
unmodulated carrier to the level contained within the calibration file and then
suddenly
From: Pawson, James
Sent: 20 August 2012 10:54
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] 61000-4-3: Rate of application of field
Hello,
I can't find any clauses in 61000-4-3 (radiated RF immunity) that deal with the
rate of application of the RF field.
My understanding
Based on my experiences with HDMI I've found the high speed TMDS interface used
on DVI (and HDMI) can be very difficult to control indeed.
Cable backshell shielding is critical to low radiated emissions. 360º
continuous shielding between cable shield and connector shell is required.
Finding a
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 of the
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
When explaining to my (non-technical) friends what I do (EMC Engineer), I
usually say something along the lines of:
You know when you put your mobile next to your speakers and it goes
da-da-da-da-daaa-da-da? My job is to stop that happening to the things we
make. We can't interfere with
Hi Derek,
I'm glad you managed to find out what had been causing that problem. Why did
you elect to have a separate chassis plane in the first place that
(presumably) wasn't tied into the PCB ground planes? My (limited) understanding
is that it is better to have all ground planes connected
Hi Julian,
EN55032 notes in table B.3 that the 10% utilisation is specifically for
10Base-T Ethernet traffic which is electrically mostly inactive when not
transmitting data.
100Base-T and 1000Base-T both use scrambled_idle packets to maintain a 0V DC
bias of the AC coupled Ethernet bus
Hello Ravinder,
I wasn't going to answer this as you were asking the experts ;)
Flip chips couple very well into their heatsinks compared to older wirebond
packages as the silicon is much closer to the top surface. Perhaps try
grounding/decoupling the heatsink or changing to a ceramic material
Hello Tom,
Very helpful (and clever), I shall gladly put these to use!
Many thanks!
James Pawson
EchoStar Europe
-Original Message-
From: T.Sato [mailto:vef00...@nifty.ne.jp]
Sent: 05 April 2014 08:51
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] CISPR 32, colour bar with moving
Hi Brent,
Even HDMI test sources like Quantum Data or Agilent machines are noisy and/or
have average signal quality.
Your cables will be a significant factor, expensive =/= well shielded. But it
sounds like you know this already.
Shopping around and doing lots of testing would probably be your
Hi all,
Our two R+S EMI receivers (ESHS ESVS) are due for calibration and I've got a
spread of quotes from various labs. It seems like each lab has a different set
of tests that they apply.
Questions:
1) Does anyone know if there is a standard calibration routine for EMI
receivers or,
I'm with Ghery on this one.
All HDMI cables are not created equal.
Screening of the backshell and connection of the cable shield is critical.
James
-Original Message-
From: Pettit, Ghery [mailto:ghery.pet...@intel.com]
Sent: 04 September 2014 08:46
To: EMC-PSTC@LISTSERV.IEEE.ORG
But John, HDMI uses a differential signalling interface which is known to
provide low emissions! 8-)
-Original Message-
From: John Woodgate [mailto:j...@jmwa.demon.co.uk]
Sent: 04 September 2014 19:44
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] FCC EMI Test and Ferrites on
That's the problem with acronyms and abbreviations, they can mean different
things to different people.
From: Pettit, Ghery [mailto:ghery.pet...@intel.com]
Sent: 28 October 2014 17:00
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] CE-magazine
I suspect he is looking for Compliance
Hi all,
We are in the market for a second hand screened room in the UK.
If anyone knows of any being sold please could they get in touch?
Many thanks,
James Pawson
Leading EMC Engineer
EchoStar
-
This message is from the IEEE
Hi Amund, a quick brain dump for you
If the emissions are caused by imbalance in the differential signal then a
Common Mode Choke (CMC) will probably help. Pick one with a good impedance at
the frequency of interest, 480MHz in this case but you can also expect to see
emissions at 960MHz and
Thank you to everyone who responded and clarified the issue, it is much
appreciated.
Regards,
James
From: Pawson, James
Sent: 26 March 2015 15:02
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot
Measurement?
Dear group,
When measuring
Dear group,
When measuring emissions using a Quasi Peak detector are there any regulations
or guidance concerning the amount of time one should dwell on a single
frequency for a measurement?
I know it depends on the nature of the signal. In this case, the signal of
interest results in a burst
Hi Brian,
An interesting problem. I suppose that you could perform the test at any
distance you wanted provided you correctly calibrated at the UFA plane. This
means you could get the best of both worlds in terms of UFA size and maximum
field strength.
Regards,
James
-Original
Additional thought: near/far field distances would also have to be considered.
-Original Message-
From: Pawson, James
Sent: 11 May 2015 09:19
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Radiated Immunity at 1meter distance
Hi Brian,
An interesting problem. I suppose that you
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
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
inverted.
If this was the case, could this be compensated for by subtracting 180° from
the reflected ground ray to ensure the phases added/subtracted correctly at the
RX antenna?
Thanks again
James
_
From: Pawson, James
Sent: 31 July 2015 15:59
Hi Brent,
In my experience from sourcing and testing many standard HDMI cables it is very
difficult to get a good quality shielded cable without working closely with the
vendors. At the very least a copper foil backshell with good solder termination
should be specified but better performance
/2015 3:56 AM, Pawson, James wrote:
In my experience from sourcing and testing many standard HDMI cables it is
very difficult to get a good quality shielded cable without working closely
with the vendors.
James,
You'll likely get some other been there, got the Tee shirt replies beside
mine
Hi Brian,
Is the furnace type common to all the failed pieces of equipment? If not
common, similar?
Reading on with interest
James
-Original Message-
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: 17 September 2015 14:37
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES]
Hi Ken,
Assuming your problem is radiated emissions I guess it depends at what
frequencies your problem emissions are at. If they are harmonics of the USB
data then it could be poor signal balance (a common mode choke could help) or
perhaps poor cable shielding (very likely with USB). If they
Hi Ken,
I built a device to do this for monitoring audio outputs from our products when
performing immunity tests for the EN55020 Broadcast Receiver Immunity standard,
measuring 1kHz breakthrough. 6 input channels with a 1kHz active bandpass
filter on each, output rectified and fed into a
ecific radios with specific
channel bandwidths, and the issue is to properly specify a measurement BW, and
what happens when the measurement BW is improperly specified (measurement BW <
radio channel BW).
Ken Javor
Phone: (256) 650-5261
____
From: "Pawson, Jame
As a young and naïve student I once used hot melt glue.
There's a clue in the name kids!
James
-Original Message-
From: Scott Xe [mailto:scott...@gmail.com]
Sent: 26 February 2016 16:53
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Reliable means to attach thermocouple to object
I
About 2.8x10^17 Joules for a gallon of petrol using E = mc^2
This is why I'm always disappointed by the mpg of my car
James
-Original Message-
From: Macy [mailto:m...@basicisp.net]
Sent: 19 February 2016 17:59
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] Energy in certain items
Does
Tablestakes.
http://annoyingpr.tumblr.com/post/13776378688/table-stakes
-Original Message-
From: Marko Radojicic [mailto:052300254e41-dmarc-requ...@ieee.org]
Sent: 11 March 2016 01:02
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] NEBS GR1089 for Remote Radio Heads
NEBS
Brian,
I feel your pain and share Rodney's opinions on HDMI cables which are my man
bugbear. Depending on how many you purchase a year or at a time you may well
find some cable companies willing to work with you.
James
-Original Message-
From: Kunde, Brian
In relation to this discussion, what is the significance of the vertical lines
either side of the |L| or |N|?
Google doesn't recognise it as a searchable term, possibly thinks it is a
logical OR symbol?
Thanks
James
From: Elliott Martinson [mailto:elliott.martin...@etcconnect.com]
Sent: 30
Hello all,
I have some questions about anechoic chambers that I need some help with and
I'm sure there is some expertise in this group that can help.
1) My understanding is that an anechoic chamber is meant to simulate a
reflection-less, free space environment. Therefore if you move a
and EUT wall.
Any criticisms of the work or methods used or thoughts on what else I could try
to establish if this is the case would be most welcomed.
Many thanks
James
_
From: Pawson, James
Sent: 29 April 2016 08:14
To: EMC-PSTC@LISTSERV.IEEE.ORG
Ken,
Jitter can be a very complicated subject; we once received a detailed and
complex presentation from LeCroy (now Teledyne) on the different types of
jitter and how you could separate them out from each other e.g. random jitter,
deterministic jitter, etc. It had more pictures and detail
Hello fellow engineers,
With an eye on the future, I am considering taking an iNARTE EMC qualification.
Specifically, I'm considering one (or possibly both) of these accreditations.
- iNARTE EMC Design Engineer Certification
- iNARTE Electromagnetic Compatibility (EMC/EMI)
Hello all,
I've been interested to see the range of comments on this question. Thank you
all for taking the time to help. I'm going to investigate further!
Regards,
James
_
From: Pawson, James
Sent: 10 August 2016 17:01
To: EMC-PSTC@LISTSERV.IEEE.ORG
Windows for Submarines
http://www.theregister.co.uk/2008/12/16/windows_for_submarines_rollout/
Good job our nuclear "deterrent" isn't safety critical!
From: Nyffenegger, Dave [mailto:dave.nyffeneg...@bhemail.com]
Sent: 04 August 2016 19:46
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES]
No mention of what band (2.4GHz or 5GHz) is affecting the monitor. I’d agree
with Stephen’s assessment in that it’s a bit of both.
From: Kortas, Jamison [mailto:jamison.kor...@ecolab.com]
Sent: 30 January 2017 16:50
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] New LG Monitors and Wi-Fi
What
Hi John,
You are right about impedance discontinuities being a factor.
However, in my experience with HDMI, these changes are swamped by a combination
of SI imperfections made up of intra pair skew, amplitude imbalance and uneven
rise/fall times within the HDMI data pairs. Adding common mode
Morning Gary,
In my experience noise resistance will depend on many factors e.g. self vs
mutual capacitance method, the cap touch device selected, sensor design, etc.
The major design trade-offs are sensitivity and speed of response vs noise
resistance and available panel size. Cap touch tends
Thanks for the link to that paper Rich, it makes for interesting reading in
plain English.
James
From: Richard Nute [mailto:ri...@ieee.org]
Sent: 20 September 2016 21:18
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Measurement Accuracy
…
I didn’t know what “uncertainty” is, so I did a
This article in The Guardian is related to your first point regarding human
drivers “gaming” driverless cars to gain an advantage
https://www.theguardian.com/technology/2016/oct/30/volvo-self-driving-car-autonomous
“The first self-driving cars to be operated by ordinary British drivers will be
Ah, hello 742.5MHz my old friend.
Alfred’s analysis in his email is good especially regarding frame rate. If you
look in the 1.4 HDMI standard in section 5.1.2 you can see that the “vertical
blanking” period consists of 45 lines. A breakdown of what’s contained within
follows below that
Hi Brent,
I've had some success with a (now slightly old) Samsung 4k TV that wasn't too
noisy, model UE48JU7000T.
James
From: Brent DeWitt [mailto:bdew...@ix.netcom.com]
Sent: 10 January 2017 01:57
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] lowest emissions 4k TV?
Hi group,
Any
60 matches
Mail list logo
