Dear colleagues;
I would like to thank all those who replied to my predicament regarding
emissions from an Ethernet port.
I have had some first-class advice which will help me solve the problem.
Many thanks;
Ian McBurney.
Allen Heath Limited.
email: ian.mcbur...@allen-heath.com
***LEGAL
Ian,
A signal that strong suggests one possibility to me. It is possible
that the board layout was automatically routed. As a result a clock
trace was run through the Ethernet magnetics area. This area should
be clear of everything but the Ethernet signals. The application
notes for the
Ian,
the question you posted is so generic that nobody can really answer it. It
does not give any clue regarding the sources and mechanisms of emission, no
results of your troubleshooting, nor does it give any insight into the product
and possible causes of the increased emission. If you
-485-2537
fax: 858-485-3788
_
From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org] On Behalf Of
Ken Javor
Sent: Friday, June 17, 2005 5:30 AM
To: McBurney, Ian [Allen Heath UK]; emc-p...@ieee.org
Subject: Re: ethernet radiated emissions
No experience with Ethernet per se
-emc-p...@ieee.org]On Behalf Of
McBurney, Ian [Allen Heath UK]
Sent: Freitag, 17. Juni 2005 13:17
To: emc-p...@ieee.org
Subject: ethernet radiated emissions
Dear colleagues;
Can anyone advise me how to reduce the radiated emissions from a 100 base-T
Ethernet port with a UTP cable connected
: ethernet radiated emissions
Dear colleagues;
Can anyone advise me how to reduce the radiated emissions from a 100 base-T
Ethernet port with a UTP cable connected to below the EN55022 class B limit?
At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the
emissions by 6dB
List-Post: emc-pstc@listserv.ieee.org
Date: Fri, 17 Jun 2005 12:17:17 +0100
To: emc-p...@ieee.org
Subject: ethernet radiated emissions
Dear colleagues;
Can anyone advise me how to reduce the radiated emissions from a 100 base-T
Ethernet port with a UTP cable connected to below the EN55022 class
Dear colleagues;
Can anyone advise me how to reduce the radiated emissions from a 100 base-T
Ethernet port with a UTP cable connected to below the EN55022 class B limit?
At the moment I am 20dB above the limit at 33MHz. Using STP only reduces the
emissions by 6dB.
Thanks in advance;
Ian
I read in !emc-pstc that neve...@attbi.com wrote (in 20021011040337.NIT
V4193.rwcrmhc51.attbi.com@rwcrwbc69) about 'Ethernet Radiated
Emissions' on Fri, 11 Oct 2002:
Second, I recommend refraining from sarcastic comments
in this forum, since that doesn't seem it was about
naivety
Pardon my naivety, but how does '100 Mbit' relate to
frequencies of 30 and 60 kHz? Is this 100 Mbit per week?
(;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk
snip
First, a little background on auto negotiation. The IEEE
802.3u 100BaseTX auto
[ Neven wrote ]
You are seing a spectrum of MLT3 signal, which is 100
Mbit coding.
[ John wrote ]
Pardon my naivety, but how does '100 Mbit' relate to frequencies
of 30 and 60 kHz? Is this 100 Mbit per week? (;-)
Could be plenty. I'd guess is something to do with either jitter and/or
I read in !emc-pstc that neve...@attbi.com wrote (in 20021010021029.WVI
M20316.sccrmhc03.attbi.com@rwcrwbc56) about 'Ethernet Radiated
Emissions' on Thu, 10 Oct 2002:
You are seing a spectrum of MLT3 signal, which is 100
Mbit coding.
Pardon my naivety, but how does '100 Mbit' relate
: Andy White (EWU) [mailto:andy.wh...@ewu.ericsson.se]
Sent: Wednesday, October 09, 2002 3:39 PM
To: Rick Linford
Subject: RE: Ethernet Radiated Emissions
Hi Rick,
Is the problem only when you link more than 2 cables together? What is the
length of link cabling when adding cables? I
]
Sent: Wednesday, October 09, 2002 3:39 PM
To: Rick Linford
Subject: RE: Ethernet Radiated Emissions
Hi Rick,
Is the problem only when you link more than 2 cables together? What is the
length of link cabling when adding cables? I susepect that the BB noise is
directly associated
I read in !emc-pstc that rlinf...@sonicwall.com wrote (in D5FCAC81D18F0
d4e8e7df3734de064f2375...@usexch3.us.sonicwall.com) about 'Ethernet
Radiated Emissions' on Wed, 9 Oct 2002:
With all cables attached and not linked there is no broadband. Reducing the
resolution shows peaks every 60 kHz
Having worked on Ethernet (100 MB UTP) EMC for a few years, I now find myself
lacking understanding of Ethernet communications and how this may be affecting
radiated emissions.
What is seen on the OATs is broadband noise between 50 and 150 MHz. With two
cables connected and linked, broadband
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