The source of more than one reflection on a OATS? Assuming a qualified one.
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John Woodgate j...@jmwa.demon.co.uk wrote:
In message 1324698614.11231.yahoomail...@web39603.mail.mud.yahoo.com,
dated Fri, 23 Dec 2011, Bill Owsley wdows...@yahoo.com writes:
For
In message 7jpsxeqh5dbij3wxd68i7qx7.1324741388...@email.android.com,
dated Sat, 24 Dec 2011, Lg wdows...@yahoo.com writes:
The source of more than one reflection on a OATS? Assuming a qualified
one.
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Please look at the subject line. I must remember that
The subject did evolve a bit. So apply to a SAC. And watch out for those
elves... /;-)
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John Woodgate j...@jmwa.demon.co.uk wrote:
In message 7jpsxeqh5dbij3wxd68i7qx7.1324741388...@email.android.com,
dated Sat, 24 Dec 2011, Lg wdows...@yahoo.com writes:
It's relevant to understand between vertically polarized waves
that have a 180 degree phase shift on reflection,
and horizontally polarized waves that do not.
Regards,
Ing. Gert Gremmen, BSc
g.grem...@cetest.nl
www.cetest.nl
Kiotoweg 363
3047 BG Rotterdam
T 31(0)104152426
F 31(0)104154953
/23/2011 02:20 AM
Subject:
Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
It's relevant to understand between vertically polarized waves
that have a 180 degree phase shift on reflection,
and horizontally polarized waves that do not.
Regards,
Ing. Gert Gremmen, BSc
g.grem
And the effect of this phase shift, or no phase shift, would be...???
From: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl
To: John Woodgate j...@jmwa.demon.co.uk; EMC-PSTC@LISTSERV.IEEE.ORG
Sent: Friday, December 23, 2011 4:58 AM
Subject:
Constructive vs. destructive interference.
Ken Javor
Phone: (256) 650-5261
From: Bill Owsley wdows...@yahoo.com
Reply-To: Bill Owsley wdows...@yahoo.com
Date: Fri, 23 Dec 2011 19:25:13 -0800 (PST)
To: ce-test, qualified testing bv - Gert Gremmen g.grem...@cetest.nl,
John Woodgate
Ah yes, theory is one thing. It will give us the ideal approximation, using its
stated assumptions. But then there is the real EUT and all of its variables.
How one correction factor of one EUT, or a noise source, etc. correlates to the
next one is a rather WAG.
For example, 3m FAC to 3m OATS
us in the choir know that. I'm curious about Gerts response since he brought it
up twice.
I've heard there is more but didn't follow the math for the proof, but the word
description made sense.
It is interesting in theoretical sense, and in a specific
practical experiment to demonstrate it, but
In message 1324698614.11231.yahoomail...@web39603.mail.mud.yahoo.com,
dated Fri, 23 Dec 2011, Bill Owsley wdows...@yahoo.com writes:
For example, 3m FAC to 3m OATS might be as much as 6 dB higher
neglecting all the previous mentioned reasons why it cannot be that much
A single reflection can
This has me bemused; when I was new in the trade, I worked for Wang Labs
in Tewksbury, Massachusetts. In fact, I got into the trade there (during
the interview i asked to be allowed to play with the receiver -- fun!)...
Our chamber was not tall enough to raise antennas to 4 meters; the
thing
over and over again and expecting different results.
From: Bill Owsley [mailto:wdows...@yahoo.com]
Sent: Wednesday, December 21, 2011 11:02 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Go back, way back, to the paper by pate, german
In message 1324530145.50231.yahoomail...@web39603.mail.mud.yahoo.com,
dated Wed, 21 Dec 2011, Bill Owsley wdows...@yahoo.com writes:
Thus, the received voltage received via a direct path added with a
reflected path, assuming no distance or reflection loss, would be 6 dB
higher than the direct
@LISTSERV.IEEE.ORG
Conversation: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Subject: RE: [PSES] Semi-Anechoic Chamber Question - Correction Factor
Bill,
I¹d guess 6dB as in voltage, with dBuV being used.
Michael Sundstrom
OHD / TREQ Dallas
Electronic Lab Analyst, EMC Lead
2170 French
30 meters. The
difference was a nominal 6dB.
Bob R.
--- On Thu, 12/22/11, Sundstrom, Michael michael_sundst...@overheaddoor.com
wrote:
From: Sundstrom, Michael michael_sundst...@overheaddoor.com
Subject: RE: [PSES] Semi-Anechoic Chamber Question - Correction Factor
To: Bill Owsley wdows
On 12/22/2011 9:27 AM, John Woodgate wrote:
If the direct and reflected rays are equal amplitude and in phase,
then it's +6 dB; if they are at 180 degrees, it's minus infinity dB.
In between you can get any value, depending on relative phase and
transmission loss.
Equal amplitude only occurs
In message 4ef37136.5070...@earthlink.net, dated Thu, 22 Dec 2011,
Cortland Richmond k...@earthlink.net writes:
On 12/22/2011 9:27 AM, John Woodgate wrote:
If the direct and reflected rays are equal amplitude and in phase,
then it's +6 dB; if they are at 180 degrees, it's minus infinity dB.
Professor Leferink published a nice paper that proposed a different correction
factor for a SAC to a FAC. I tried to track it down but had no luck.
Best Regards
Charles Grasso
Compliance Engineer
Echostar Communications
(w) 303-706-5467
(c) 303-204-2974
(t)
Go back, way back, to the paper by pate, german, smith, on the NSA.
Go through all the details and calculations and surmise that there is the
direct path, and the reflected path.
The reflected path adds, or not, to the direct path, depending on wavelength
(phase at receive antenna) and distance
At a basic level, do an NSA for the chamber and compare to the OATS NSA to
develop a correction factor for the two.
From: Grasso, Charles charles.gra...@echostar.com
To: Jim Hulbert jim.hulb...@pb.com; EMC-PSTC@LISTSERV.IEEE.ORG
EMC-PSTC@LISTSERV.IEEE.ORG
I echo Ken's suggestion.
The Other Brian
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken Javor
Sent: Friday, December 16, 2011 6:04 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: Semi-Anechoic Chamber Question
Since it's a pre-compliance scan, why not just leave the floor
regards,
Mac Elliott
[] General Public
From: Kunde, Brian [mailto:brian_ku...@lecotc.com]
Sent: Monday, December 19, 2011 9:01 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Semi-Anechoic Chamber Question
I echo Ken's suggestion.
The Other Brian
From: emc-p
[mailto:brian_ku...@lecotc.com]
Sent: Monday, December 19, 2011 9:01 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] Semi-Anechoic Chamber Question
I echo Ken’s suggestion.
The Other Brian
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken Javor
Sent: Friday
Thank you everyone for the helpful feedback. The consensus is clearly: Save my
back and leave the absorber and ferrite tiles in place. Compare radiated
emissions measurements in the chamber to those on the OATS (several suggested a
comb generator for this purpose). Assign an adjustment
Jim
As others have suggested, I'd recommend leaving you chamber as it is, HOWEVER,
I would perform correlation to OATS using some of your typical EUT, as well as
a CNE or other noisy box - I've seen 10dB difference, relative to limit,
between 3m FAC's and 10m OATS measurement when measuring an
In message
72b8947772cf0948adaa9853631663fb6473554...@pbi-namsg-02.mgdpbi.global.pv
t, dated Fri, 16 Dec 2011, Jim Hulbert jim.hulb...@pb.com writes:
As an easier option, I'm thinking of coming up with a relatively
light weight conductive surface that can be easily placed over the
floor
Since it¹s a pre-compliance scan, why not just leave the floor absorber in
place, use a fixed receive antenna height, and add 4-6 dB (or whatever
number is deemed appropriate) as a worst case adjustment factor?
Ken Javor
Phone: (256) 650-5261
From: Jim Hulbert jim.hulb...@pb.com
Date: Fri,
Hi Jim,
When I've needed a small temporary ground plane, I've found that foil backed
vapor barrier paper was cheap and a lot tougher than straight foil. It's
not terribly convenient, but it's cheap and light weight for quick and dirty
setups.
Brent DeWitt
Milford, MA
From: Jim
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