Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-11 Thread Ed Price 
Charlie:

 

Each command determines what it needs and what is important to fulfill its
mission. Of course, urgent needs could be met through using COTS, but I have
found that despite the procurement office wanting the advantages of COTS,
they still try to impose a 461 set of EMC requirements. This is sort of like
the DoD saying I want it cheap and fast, but by the way, it should also be
461 compliant.

 

The USAF has a program called Seek Eagle, which is used to certify equipment
for use on a number of aircraft. Among other techniques, they can opt to
carefully do platform integration testing, which could very possibly result
in equipment that could never pass 461 being allowed onto aircraft. This is
developmental, and anything that proved of long term desirability would
probably have to meet all the environmental requirements eventually.

 

I'll bet that other services have similar fast development paths too.

 

Ultimately, remember that 461 invokes tailoring, and if you know more about
the platform environment than the generic 461 does, you are supposed to
modify the 461 requirements to agree with the reality of the platform and
its mission. Yes, a lot of discussion is involved. J

 

Ed Price

El Cajon, CA

USA

 

 

From: Charlie Blackham [mailto:char...@sulisconsultants.com] 
Sent: Thursday, August 09, 2012 2:08 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 

Ed

 

I didn't say the US DoD would buy it J. 

Out of interest, does the US DoD operate an Urgent Operation Requirement or
similar short-cutting procurement process, as done by UK MoD,  that allows
them to bring stuff into use that has known, acceptable and mitigated  EMC
performance, but does not meet a blanket (and possibly irrelevant) "DC to
daylight" emissions/immunity level?

 

 

Regards

Charlie

 


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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-10 Thread Ed Price 
Ralph:

 

I used the ancient HP-85869PC data acquisition software, and HP (being 
conservative) used a 1 Hz RBW for implementing an Average detector. They did 
this to extend the HP-8566B’s capabilities to commercial EMI testing. (For 
Quasi Peak, they needed an external filter and detector box that was inserted 
in the 8566B’s IF chain.)

 

However, the 461 detector is always supposed to be a Peak detector. (Except for 
CS101, where the limit is expressed in terms of Vrms. OTOH, almost everyone 
uses an oscilloscope to monitor this level, so…)

 

Ed Price

El Cajon, CA

USA

 

 

From: ralph.mcdiar...@schneider-electric.com 
[mailto:ralph.mcdiar...@schneider-electric.com] 
Sent: Thursday, August 09, 2012 1:52 PM
To: edpr...@cox.net
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 


Hi Ed, 

I would have thought so too, unless 461 has an AVG limit line, in which case 
I'd use an average detector for both.   

BTW, we've found that a VBW of 10Hz does a reasonable job of emulating the 
response of an average detector defined in CISPR 16.
___ 

Ralph McDiarmid  |   Schneider Electric   |  Solar Business  |   CANADA  |   
Regulatory Compliance Engineering 
Phone: +1-604-422-2622  |   e-mail:  
<mailto:ralph.mcdiar...@schneider-electric.com> 
ralph.mcdiar...@schneider-electric.com  |   Site: 
<http://www.schneider-electric.com/>  www.schneider-electric.com  |   
Address: 3700 Gilmore Way, Burnaby, BC, V5G4M1 





From: 

Ed Price  


To: 

EMC-PSTC@LISTSERV.IEEE.ORG 


Date: 

08/09/2012 12:40 PM 


Subject: 

Re: [PSES] MIL STD 461E NECESSARY   BANDWIDTH

 

  _  




Charlie: 
  
The USA DoD procurement system uses a detailed contract to legally bind a 
vendor to a number of conditions, and in the EMC area, the successful 
performance of MIL-STD-461F is typical. The contract will call out which 
specific Test Methods (including variations) are applicable, so if CE106 is in 
the contract, believe me, it is mandatory. 
  
True, the early 461 was just taking an educated whack at controlling 
intentional emissions to nothing more than was reasonable and economical to 
achieve. There was little justification to why 5% was better than 7%, other 
than the ancient relationship to half the number of allocated fingers. (BTW, 
can you imagine a world in which 7 fingers or toes per hand or foot gave rise 
to a base 14 numerical system?) 
  
Lastly, why would you use a different RBW to measure the fundamental versus the 
spurious emissions? I would think that the only way to accurately measure the 
peak of a spurious was the same way that you measured the peak of the 
fundamental. 
  
Ed Price 
El Cajon, CA 
USA 
  
  
From: Charlie Blackham [ <mailto:char...@sulisconsultants.com> 
mailto:char...@sulisconsultants.com] 
Sent: Thursday, August 09, 2012 1:26 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH 
  
ETSI standards typically define “Spurious Emissions” as being those removed 
from cF by >250% of the necessary bandwidth. 
  
Emissions within this region are typically covered by Spectral Mask and 
Occupied Bandwidth requirements, both of which are typically measured using 
much lower RBWs than used for Spurious Emissions so that accurate measurements 
can be obtained. 
  
I’m might be talking out of my hat now, but when MIL-STD-461 was first written 
way back when, I’m sure that they were really only thinking in terms of AM/FM 
modulation - 40 MHz wide OFDM and 1GHz wide FMCW devices weren’t probably 
envisaged. 
  
Since, in my experience, CE106 isn’t actually Mandatory for selling a product, 
I would do the test in a way that seems reasonable for the operation of your 
product, document what you’ve done and why, and discuss/explain to customers as 
required. 
  
You might want to have a look at CEPT/ERC/REC 74-01 and associated documents 
  
Regards 
Charlie 
  
  
From: Mazzola, Santo (US SSA)  <mailto:[mailto:santo.mazz...@baesystems.com]> 
[mailto:santo.mazz...@baesystems.com] 
Sent: 07 August 2012 00:21
To:  <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH 
  
Airy, 
  
In MIL-STD-461F they changed the language of the exception, It now reads: 
The transmit mode portion of this requirement is not applicable within the 
bandwidth 
of the EUT transmitted signal or within ±5 percent of the fundamental 
frequency, whichever is 
larger. 
So if the necessary bandwidth is greater then +/- 5% it is still excluded. 
  
Speaking in generalities, the necessary bandwidth of whatever kind of 
transmitter it is, probably has some kind of Spectral mask requirement that is 
not a MIL-STD-461 requirement.  The spurious emissions requirements of CE106 
cannot begin until after the necessary bandwidth ends. 
  
Hope that helps. 
  
Sandy (Santo) Mazzola   
EMC Engineer 
BAE Systems Inc

Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Charlie Blackham 
Ed

I didn't say the US DoD would buy it :).
Out of interest, does the US DoD operate an Urgent Operation Requirement or 
similar short-cutting procurement process, as done by UK MoD,  that allows them 
to bring stuff into use that has known, acceptable and mitigated  EMC 
performance, but does not meet a blanket (and possibly irrelevant) "DC to 
daylight" emissions/immunity level?

MIL-STD EMC and Environmental qualifications are accepted by a number of 
customers world wide, other than DoD,  and there are military radios that don't 
pass CE106 (indeed,  given constrains of their size, could not pass it) being 
sold quite successfully.
Where there is an unusual technology, or unclear application of the standard, I 
would expect there to be a discussion between manufacturer and end customer as 
to what was actually required and how compliance would be demonstrated.

Spurious Emission limits are normally expressed with regard to a specific 
measurement bandwidth, rather than product related bandwidth because they are 
really there to limit noise in the radio spectrum - without particularly caring 
what caused them.
There are typically higher limits for devices operating in licensed bands than 
unlicensed because there is some control over the use of the former and they 
are typically present in lower density (devices per unit of area).

Regards
Charlie


From: Ed Price [mailto:edpr...@cox.net]
Sent: 09 August 2012 20:38
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

Charlie:

The USA DoD procurement system uses a detailed contract to legally bind a 
vendor to a number of conditions, and in the EMC area, the successful 
performance of MIL-STD-461F is typical. The contract will call out which 
specific Test Methods (including variations) are applicable, so if CE106 is in 
the contract, believe me, it is mandatory.

True, the early 461 was just taking an educated whack at controlling 
intentional emissions to nothing more than was reasonable and economical to 
achieve. There was little justification to why 5% was better than 7%, other 
than the ancient relationship to half the number of allocated fingers. (BTW, 
can you imagine a world in which 7 fingers or toes per hand or foot gave rise 
to a base 14 numerical system?)

Lastly, why would you use a different RBW to measure the fundamental versus the 
spurious emissions? I would think that the only way to accurately measure the 
peak of a spurious was the same way that you measured the peak of the 
fundamental.

Ed Price
El Cajon, CA
USA


From: Charlie Blackham 
[mailto:char...@sulisconsultants.com]<mailto:[mailto:char...@sulisconsultants.com]>
Sent: Thursday, August 09, 2012 1:26 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

ETSI standards typically define "Spurious Emissions" as being those removed 
from cF by >250% of the necessary bandwidth.

Emissions within this region are typically covered by Spectral Mask and 
Occupied Bandwidth requirements, both of which are typically measured using 
much lower RBWs than used for Spurious Emissions so that accurate measurements 
can be obtained.

I'm might be talking out of my hat now, but when MIL-STD-461 was first written 
way back when, I'm sure that they were really only thinking in terms of AM/FM 
modulation - 40 MHz wide OFDM and 1GHz wide FMCW devices weren't probably 
envisaged.

Since, in my experience, CE106 isn't actually Mandatory for selling a product, 
I would do the test in a way that seems reasonable for the operation of your 
product, document what you've done and why, and discuss/explain to customers as 
required.

You might want to have a look at CEPT/ERC/REC 74-01 and associated documents

Regards
Charlie


From: Mazzola, Santo (US SSA) 
[mailto:santo.mazz...@baesystems.com]<mailto:[mailto:santo.mazz...@baesystems.com]>
Sent: 07 August 2012 00:21
To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

Airy,

In MIL-STD-461F they changed the language of the exception, It now reads:
The transmit mode portion of this requirement is not applicable within the 
bandwidth
of the EUT transmitted signal or within ±5 percent of the fundamental 
frequency, whichever is
larger.
So if the necessary bandwidth is greater then +/- 5% it is still excluded.

Speaking in generalities, the necessary bandwidth of whatever kind of 
transmitter it is, probably has some kind of Spectral mask requirement that is 
not a MIL-STD-461 requirement.  The spurious emissions requirements of CE106 
cannot begin until after the necessary bandwidth ends.

Hope that helps.

Sandy (Santo) Mazzola
EMC Engineer
BAE Systems Inc


From: emc-p...@ieee.org<mailto:emc-p...@ieee.org> 
[mailto:emc-p...@ieee.org]<mailto:[mailto:emc-p...@ieee.org]> On Behalf Of 
Airy, Chad

Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread John Woodgate 
In message 
lectric.com>, dated Thu, 9 Aug 2012, 
ralph.mcdiar...@schneider-electric.com writes:



Anyone know how big a 10-penny nail is?


Very small, these days, because the name indicates that you get 10 for a 
penny.

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
Instead of saying that the government is doing too little, too late or too
much, too early, say they've got is exactly right, thus throwing them into
total confusion.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

-

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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Ed Price 
10-penny nail is 7.62 cm long, or as we say it, 3 inches. But I prefer to
build with deck screws; a power tool is involved, and I don't have to hit it
straight.

 

Ed Price

El Cajon, CA

USA

 

 

From: ralph.mcdiar...@schneider-electric.com
[mailto:ralph.mcdiar...@schneider-electric.com] 
Sent: Thursday, August 09, 2012 1:31 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 


It wasn't long ago that NASA was still using units like "slugs" in their
technical publications. 

The metric system doesn't really impress me any more that does the Imperial
system.  Whatever you're used 
to working with, works just fine.I don't see advantage in one system of
measurement over 
another, but there are number systems which have obvious benefits.  The
binary number system for Boolean algebra 
seems the only good fit for instance. 

Anyone know how big a 10-penny nail is?

___ 

Ralph McDiarmid  |   Schneider Electric   |  Solar Business  |   CANADA  |
Regulatory Compliance Engineering 





-

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.

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Instructions:  http://listserv.ieee.org/request/user-guide.html
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Scott Douglas 
Mike Cantwell 

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

Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Ralph . McDiarmid 
It wasn't long ago that NASA was still using units like "slugs" in their 
technical publications.

The metric system doesn't really impress me any more that does the 
Imperial system.  Whatever you're used
to working with, works just fine.I don't see advantage in one system 
of measurement over
another, but there are number systems which have obvious benefits.  The 
binary number system for Boolean algebra 
seems the only good fit for instance.

Anyone know how big a 10-penny nail is?
___ 


Ralph McDiarmid  |   Schneider Electric   |  Solar Business  |   CANADA  | 
  Regulatory Compliance Engineering 




From:
John Woodgate 
To:
EMC-PSTC@LISTSERV.IEEE.ORG
Date:
08/09/2012 01:19 PM
Subject:
Re: [PSES] MIL STD 461E NECESSARY   BANDWIDTH



In message <005a01cd7666$84d0a360$8e71ea20$@cox.net>, dated Thu, 9 Aug 
2012, Ed Price  writes:

>(BTW, can you imagine a world in which 7 fingers or toes per hand or 
>foot gave rise to a base 14 numerical system?)

Not needed: human ingenuity is boundless. Counting in different bases 
was endemic in the good old pre-metric days, regardless of fingers. 16 
ounces = 1 lb (pound), 14 lb = 1 stone, 28 lb = 1 quarter, 4 quarters 1 
hundredweight. In fact, I don't think base 10 appears anywhere is 
Imperial measure, not even in obscure units like fardels and nootes.

In France and Germany, the livre and Pfund (of 500 gm) are still quietly 
used.
-- 
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
Instead of saying that the government is doing too little, too late or too
much, too early, say they've got is exactly right, thus throwing them into
total confusion.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

-

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://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html

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Mike Cantwell 

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All emc-pstc postings are archived and searchable on the web at:
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formats), large files, etc.

Website:  http://www.ieee-pses.org/
Instructions:  http://listserv.ieee.org/request/user-guide.html
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Mike Cantwell 

For policy questions, send mail to:
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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread John Woodgate 
In message <005a01cd7666$84d0a360$8e71ea20$@cox.net>, dated Thu, 9 Aug 
2012, Ed Price  writes:


(BTW, can you imagine a world in which 7 fingers or toes per hand or 
foot gave rise to a base 14 numerical system?)


Not needed: human ingenuity is boundless. Counting in different bases 
was endemic in the good old pre-metric days, regardless of fingers. 16 
ounces = 1 lb (pound), 14 lb = 1 stone, 28 lb = 1 quarter, 4 quarters 1 
hundredweight. In fact, I don't think base 10 appears anywhere is 
Imperial measure, not even in obscure units like fardels and nootes.


In France and Germany, the livre and Pfund (of 500 gm) are still quietly 
used.

--
OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk
Instead of saying that the government is doing too little, too late or too
much, too early, say they've got is exactly right, thus throwing them into
total confusion.
John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK

-

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://listserv.ieee.org/request/user-guide.html
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] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Ken Javor 
Ed,

Thanks for addressing the contractual nature of CE106 in particular and
MIL-STD-461 in general.  You saved me the effort.

EMC Compliance has a set of very old tunable notch filters specifically
designed for CE106 measurements by Empire Devices for use with the NF-105.
These are two pole filters: a cap and a choke.  If you measure the insertion
loss curve for these simple devices, that old 5% pretty well covers the
frequency range where the insertion loss departs from 0 dB...
  
Ken Javor
Phone: (256) 650-5261



From: Ed Price 
Organization: ESP Labs
Reply-To: 
Date: Thu, 9 Aug 2012 12:38:14 -0700
To: 
Subject: RE: [PSES] MIL STD 461E NECESSARY   BANDWIDTH

Charlie:
 
The USA DoD procurement system uses a detailed contract to legally bind a
vendor to a number of conditions, and in the EMC area, the successful
performance of MIL-STD-461F is typical. The contract will call out which
specific Test Methods (including variations) are applicable, so if CE106 is
in the contract, believe me, it is mandatory.
 
True, the early 461 was just taking an educated whack at controlling
intentional emissions to nothing more than was reasonable and economical to
achieve. There was little justification to why 5% was better than 7%, other
than the ancient relationship to half the number of allocated fingers. (BTW,
can you imagine a world in which 7 fingers or toes per hand or foot gave
rise to a base 14 numerical system?)
 
Lastly, why would you use a different RBW to measure the fundamental versus
the spurious emissions? I would think that the only way to accurately
measure the peak of a spurious was the same way that you measured the peak
of the fundamental.
 

Ed Price
El Cajon, CA
USA
 
 

From: Charlie Blackham [mailto:char...@sulisconsultants.com]
Sent: Thursday, August 09, 2012 1:26 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH
 
ETSI standards typically define ³Spurious Emissions² as being those removed
from cF by >250% of the necessary bandwidth.
 
Emissions within this region are typically covered by Spectral Mask and
Occupied Bandwidth requirements, both of which are typically measured using
much lower RBWs than used for Spurious Emissions so that accurate
measurements can be obtained.
 
I¹m might be talking out of my hat now, but when MIL-STD-461 was first
written way back when, I¹m sure that they were really only thinking in terms
of AM/FM modulation - 40 MHz wide OFDM and 1GHz wide FMCW devices weren¹t
probably envisaged.
 
Since, in my experience, CE106 isn¹t actually Mandatory for selling a
product, I would do the test in a way that seems reasonable for the
operation of your product, document what you¹ve done and why, and
discuss/explain to customers as required.
 
You might want to have a look at CEPT/ERC/REC 74-01 and associated documents
 
Regards
Charlie
 
 

From: Mazzola, Santo (US SSA) [mailto:santo.mazz...@baesystems.com]
Sent: 07 August 2012 00:21
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH
 
Airy,
 
In MIL-STD-461F they changed the language of the exception, It now reads:
The transmit mode portion of this requirement is not applicable within the
bandwidth
of the EUT transmitted signal or within ±5 percent of the fundamental
frequency, whichever is
larger.
So if the necessary bandwidth is greater then +/- 5% it is still excluded.
 
Speaking in generalities, the necessary bandwidth of whatever kind of
transmitter it is, probably has some kind of Spectral mask requirement that
is not a MIL-STD-461 requirement.  The spurious emissions requirements of
CE106 cannot begin until after the necessary bandwidth ends.
 
Hope that helps.
 
Sandy (Santo) Mazzola
EMC Engineer
BAE Systems Inc
 
 

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Airy, Chad
Sent: Monday, August 06, 2012 6:44 PM
To: emc-p...@ieee.org
Subject: MIL STD 461E NECESSARY BANDWIDTH
 
Greetings,
Greetings to all, this is my first post to the list.
My question deals with the Applicability paragraph of CE106.  How does one
apply the +/-5% non-applicability rule when the necessary bandwidth exceeds
10% of the fundamental frequency by a fair margin?
Quoting the standard:
²The transmit mode portion of this requirement is not applicable within the
EUT necessary bandwidth and within ±5 percent of the fundamental frequency.²
 
The case I am referring to is real.  However, to prevent exposure of
proprietary information, I will use a hypothetical example:
An airborne synthetic aperture radar having a fixed nominal chirp bandwidth
of 1500 MHz at a center frequency of 15 GHz, illuminates a  designated area
on the ground. The radar fly¹s by the area, capturing multiple images, each
from different depression and squint angles.  During the transit of the
imaging path, the radar center frequency and chirp bandwidth are gradually
shifted for the purpose of improving the image quality. The resulting
envelope of occupied (chirp BW + center freq shift) is 2

Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Ed Price 
Charlie:

 

The USA DoD procurement system uses a detailed contract to legally bind a
vendor to a number of conditions, and in the EMC area, the successful
performance of MIL-STD-461F is typical. The contract will call out which
specific Test Methods (including variations) are applicable, so if CE106 is
in the contract, believe me, it is mandatory.

 

True, the early 461 was just taking an educated whack at controlling
intentional emissions to nothing more than was reasonable and economical to
achieve. There was little justification to why 5% was better than 7%, other
than the ancient relationship to half the number of allocated fingers. (BTW,
can you imagine a world in which 7 fingers or toes per hand or foot gave
rise to a base 14 numerical system?)

 

Lastly, why would you use a different RBW to measure the fundamental versus
the spurious emissions? I would think that the only way to accurately
measure the peak of a spurious was the same way that you measured the peak
of the fundamental.

 

Ed Price

El Cajon, CA

USA

 

 

From: Charlie Blackham [mailto:char...@sulisconsultants.com] 
Sent: Thursday, August 09, 2012 1:26 AM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 

ETSI standards typically define “Spurious Emissions” as being those removed
from cF by >250% of the necessary bandwidth.

 

Emissions within this region are typically covered by Spectral Mask and
Occupied Bandwidth requirements, both of which are typically measured using
much lower RBWs than used for Spurious Emissions so that accurate
measurements can be obtained.

 

I’m might be talking out of my hat now, but when MIL-STD-461 was first
written way back when, I’m sure that they were really only thinking in terms
of AM/FM modulation - 40 MHz wide OFDM and 1GHz wide FMCW devices weren’t
probably envisaged.

 

Since, in my experience, CE106 isn’t actually Mandatory for selling a
product, I would do the test in a way that seems reasonable for the
operation of your product, document what you’ve done and why, and
discuss/explain to customers as required.

 

You might want to have a look at CEPT/ERC/REC 74-01 and associated documents

 

Regards

Charlie

 

 

From: Mazzola, Santo (US SSA) [mailto:santo.mazz...@baesystems.com] 
Sent: 07 August 2012 00:21
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 

Airy,

 

In MIL-STD-461F they changed the language of the exception, It now reads:

The transmit mode portion of this requirement is not applicable within the
bandwidth

of the EUT transmitted signal or within ±5 percent of the fundamental
frequency, whichever is

larger.

So if the necessary bandwidth is greater then +/- 5% it is still excluded.

 

Speaking in generalities, the necessary bandwidth of whatever kind of
transmitter it is, probably has some kind of Spectral mask requirement that
is not a MIL-STD-461 requirement.  The spurious emissions requirements of
CE106 cannot begin until after the necessary bandwidth ends.

 

Hope that helps.

 

Sandy (Santo) Mazzola  

EMC Engineer

BAE Systems Inc

 

 

From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Airy, Chad
Sent: Monday, August 06, 2012 6:44 PM
To: emc-p...@ieee.org
Subject: MIL STD 461E NECESSARY BANDWIDTH

 

Greetings,

Greetings to all, this is my first post to the list. 

My question deals with the Applicability paragraph of CE106.  How does one
apply the +/-5% non-applicability rule when the necessary bandwidth exceeds
10% of the fundamental frequency by a fair margin?

Quoting the standard:

”The transmit mode portion of this requirement is not applicable within the
EUT necessary bandwidth and within ±5 percent of the fundamental frequency.”

 

The case I am referring to is real.  However, to prevent exposure of
proprietary information, I will use a hypothetical example:

An airborne synthetic aperture radar having a fixed nominal chirp bandwidth
of 1500 MHz at a center frequency of 15 GHz, illuminates a  designated area
on the ground. The radar fly’s by the area, capturing multiple images, each
from different depression and squint angles.  During the transit of the
imaging path, the radar center frequency and chirp bandwidth are gradually
shifted for the purpose of improving the image quality. The resulting
envelope of occupied (chirp BW + center freq shift) is 2000 MHz.  

 

Chad Airy

SM, IEEE EMC SOCIETY

Senior RF Engineer

EMC Lab Manager

General Atomics - RSG

OFC. 858.762.6853

-


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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-09 Thread Charlie Blackham 
ETSI standards typically define "Spurious Emissions" as being those removed 
from cF by >250% of the necessary bandwidth.

Emissions within this region are typically covered by Spectral Mask and 
Occupied Bandwidth requirements, both of which are typically measured using 
much lower RBWs than used for Spurious Emissions so that accurate measurements 
can be obtained.

I'm might be talking out of my hat now, but when MIL-STD-461 was first written 
way back when, I'm sure that they were really only thinking in terms of AM/FM 
modulation - 40 MHz wide OFDM and 1GHz wide FMCW devices weren't probably 
envisaged.

Since, in my experience, CE106 isn't actually Mandatory for selling a product, 
I would do the test in a way that seems reasonable for the operation of your 
product, document what you've done and why, and discuss/explain to customers as 
required.

You might want to have a look at CEPT/ERC/REC 74-01 and associated documents

Regards
Charlie


From: Mazzola, Santo (US SSA) [mailto:santo.mazz...@baesystems.com]
Sent: 07 August 2012 00:21
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

Airy,

In MIL-STD-461F they changed the language of the exception, It now reads:
The transmit mode portion of this requirement is not applicable within the 
bandwidth
of the EUT transmitted signal or within ±5 percent of the fundamental 
frequency, whichever is
larger.
So if the necessary bandwidth is greater then +/- 5% it is still excluded.

Speaking in generalities, the necessary bandwidth of whatever kind of 
transmitter it is, probably has some kind of Spectral mask requirement that is 
not a MIL-STD-461 requirement.  The spurious emissions requirements of CE106 
cannot begin until after the necessary bandwidth ends.

Hope that helps.

Sandy (Santo) Mazzola
EMC Engineer
BAE Systems Inc


From: emc-p...@ieee.org<mailto:emc-p...@ieee.org> 
[mailto:emc-p...@ieee.org]<mailto:[mailto:emc-p...@ieee.org]> On Behalf Of 
Airy, Chad
Sent: Monday, August 06, 2012 6:44 PM
To: emc-p...@ieee.org<mailto:emc-p...@ieee.org>
Subject: MIL STD 461E NECESSARY BANDWIDTH

Greetings,
Greetings to all, this is my first post to the list.
My question deals with the Applicability paragraph of CE106.  How does one 
apply the +/-5% non-applicability rule when the necessary bandwidth exceeds 10% 
of the fundamental frequency by a fair margin?
Quoting the standard:
"The transmit mode portion of this requirement is not applicable within the EUT 
necessary bandwidth and within ±5 percent of the fundamental frequency."

The case I am referring to is real.  However, to prevent exposure of 
proprietary information, I will use a hypothetical example:
An airborne synthetic aperture radar having a fixed nominal chirp bandwidth of 
1500 MHz at a center frequency of 15 GHz, illuminates a  designated area on the 
ground. The radar fly's by the area, capturing multiple images, each from 
different depression and squint angles.  During the transit of the imaging 
path, the radar center frequency and chirp bandwidth are gradually shifted for 
the purpose of improving the image quality. The resulting envelope of occupied 
(chirp BW + center freq shift) is 2000 MHz.

Chad Airy
SM, IEEE EMC SOCIETY
Senior RF Engineer
EMC Lab Manager
General Atomics - RSG
OFC. 858.762.6853
-


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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-07 Thread Cortland Richmond 
I would say that they refer to the INSTANTANEOUS bandwidth. Cortland Richmond-Original Message-
From: "Airy, Chad" 
Sent: Aug 6, 2012 6:43 PM
To: "emc-p...@ieee.org" 
Subject: MIL STD 461E NECESSARY   BANDWIDTH






Greetings,Greetings to all, this is my first post to the list. My question deals with the Applicability paragraph of CE106.  How does one apply the +/-5% non-applicability rule when the necessary bandwidth exceeds 10% of the fundamental frequency by a fair margin?Quoting the standard:”The transmit mode portion of this requirement is not applicable within the EUT necessary bandwidth and within ±5 percent of the fundamental frequency.” The case I am referring to is real.  However, to prevent exposure of proprietary ...     radar center frequency and chirp bandwidth are gradually shifted for the purpose of improving the image quality. The resulting envelope of occupied (chirp BW + center freq shift) is 2000 MHz.   
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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 

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Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-07 Thread Ed Price 
Chad:

 

The standard’s 5% is only a rule of thumb, a reasonable value that well
designed equipment ought to be able to comply with. OTOH, 5% was reasonable
back in the days of SSB HF or FM VHF. Modern digital modulation schemes
intentionally spread the spectrum, so we need to start with what is
technically needed to define “necessary.”

 

Necessary bandwidth is whatever you claim it is; if your 15 GHz gadget needs
1500 MHz of spectrum, then 1500 MHz is your necessary bandwidth. Only you
can determine what’s “necessary”, because only you know the amount of energy
needed to complete your job (in this case, move information into a receiver
via a ground-reflected signal path). If you system designers could do the
job by using maybe 1300 MHz of bandwidth, then they should. But, if the
modulation dictates 1500 MHz, then that’s what you require.

 

Now the frequency shift complicates things a bit. Let’s say the center
frequency is shifted (swept) plus and minus 500 MHz. Now you have a signal
that is 1500 MHz wide, and starts at a center frequency of 14.5 GHz and is
swept up to 15.5 GHz. You didn’t say how fast the sweep is, but let’s say
it’s fairly fast. You now have a necessary bandwidth of 13.75 GHz to 16.25
GHz, which is ±8%.

 

It will all come down to whether your customer thinks the value of your
device is worth the amount of spectrum that you ask for. Your customer will
prefer you always conserve weight, size, power and bandwidth, but if the
state of the art needs ±20% to get nice resolution of the shape of the bad
guys noses, then only your customer can judge the trade-off. Chances are
that your gadget will be used only in very specific environments, so your
customer will already know of any electronic systems which may be affected
by the bandwidth your gadget desires. If there is a conflict, you may be
asked to change your sweep range or rate, offset your center frequency or
implement some kind of selective power reduction.

 

So, you start out by claiming a realistic necessary bandwidth, and then be
prepared to either live with that or be ready to negotiate possible changes.


 

Ed Price

El Cajon, CA

USA

 

 

From: Airy, Chad [mailto:chad.a...@ga-asi.com] 
Sent: Monday, August 06, 2012 3:44 PM
To: EMC-PSTC@LISTSERV.IEEE.ORG
Subject: [PSES] MIL STD 461E NECESSARY BANDWIDTH

 

Greetings,

Greetings to all, this is my first post to the list. 

My question deals with the Applicability paragraph of CE106.  How does one
apply the +/-5% non-applicability rule when the necessary bandwidth exceeds
10% of the fundamental frequency by a fair margin?

Quoting the standard:

”The transmit mode portion of this requirement is not applicable within the
EUT necessary bandwidth and within ±5 percent of the fundamental frequency.”

 

The case I am referring to is real.  However, to prevent exposure of
proprietary information, I will use a hypothetical example:

An airborne synthetic aperture radar having a fixed nominal chirp bandwidth
of 1500 MHz at a center frequency of 15 GHz, illuminates a  designated area
on the ground. The radar fly’s by the area, capturing multiple images, each
from different depression and squint angles.  During the transit of the
imaging path, the radar center frequency and chirp bandwidth are gradually
shifted for the purpose of improving the image quality. The resulting
envelope of occupied (chirp BW + center freq shift) is 2000 MHz.  

 

Chad Airy

SM, IEEE EMC SOCIETY

Senior RF Engineer

EMC Lab Manager

General Atomics - RSG

OFC. 858.762.6853

-


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discussion list. To post a message to the list, send your e-mail to


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Scott Douglas 
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For policy questions, send mail to:
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For help,

Re: [PSES] MIL STD 461E NECESSARY BANDWIDTH

2012-08-06 Thread Mazzola, Santo (US SSA) 
Airy,

In MIL-STD-461F they changed the language of the exception, It now reads:
The transmit mode portion of this requirement is not applicable within the 
bandwidth
of the EUT transmitted signal or within ±5 percent of the fundamental 
frequency, whichever is
larger.
So if the necessary bandwidth is greater then +/- 5% it is still excluded.

Speaking in generalities, the necessary bandwidth of whatever kind of 
transmitter it is, probably has some kind of Spectral mask requirement that is 
not a MIL-STD-461 requirement.  The spurious emissions requirements of CE106 
cannot begin until after the necessary bandwidth ends.

Hope that helps.

Sandy (Santo) Mazzola
EMC Engineer
BAE Systems Inc


From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Airy, Chad
Sent: Monday, August 06, 2012 6:44 PM
To: emc-p...@ieee.org
Subject: MIL STD 461E NECESSARY BANDWIDTH

Greetings,
Greetings to all, this is my first post to the list.
My question deals with the Applicability paragraph of CE106.  How does one 
apply the +/-5% non-applicability rule when the necessary bandwidth exceeds 10% 
of the fundamental frequency by a fair margin?
Quoting the standard:
"The transmit mode portion of this requirement is not applicable within the EUT 
necessary bandwidth and within ±5 percent of the fundamental frequency."

The case I am referring to is real.  However, to prevent exposure of 
proprietary information, I will use a hypothetical example:
An airborne synthetic aperture radar having a fixed nominal chirp bandwidth of 
1500 MHz at a center frequency of 15 GHz, illuminates a  designated area on the 
ground. The radar fly's by the area, capturing multiple images, each from 
different depression and squint angles.  During the transit of the imaging 
path, the radar center frequency and chirp bandwidth are gradually shifted for 
the purpose of improving the image quality. The resulting envelope of occupied 
(chirp BW + center freq shift) is 2000 MHz.

Chad Airy
SM, IEEE EMC SOCIETY
Senior RF Engineer
EMC Lab Manager
General Atomics - RSG
OFC. 858.762.6853
-


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 
mailto:emc-p...@ieee.org>>

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formats), large files, etc.

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David Heald mailto:dhe...@gmail.com>>

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