Jeff,
Items 2 and 4 are probably correct. It is a very specialized subject
that most compliance people do not deal with. You have a list of 10
questions that are quite general like "are water fittings inherently
unsafe?". These probably require detailed answers that take some
research. Most qu
I am looking for a 6-slot "C" VXI mainframe with all associated optional
shielding and metalwork, if applicable, required to meet Class B emissions
limits. It will be used to help certify a customer's VXI product to EN
55022 Class B. Most VXI mainframes claim compliance only with 55011 Class
It also helps to run the antenna feed horozontally for about 2.0 - 2.5
meters before dropping it vertically to the ground plane.
-- Forwarded by Robert E. Heller/US-Corporate/3M/US on
11/13/98 03:24 PM ---
Mike and others,
EN 55022:1994/A2:1997 (CISPR 22:1993/A2:1996 Modified) contains
guidelines for site attenuation measurements of alternative sites in
normative Annex A. These measurements are volumetric measurements
which seem to follow the ANSI C63.4 volumetric m
Anybody know of a good lab (California?) that does Caller-ID testing
(per GR-30-CORE)? Our unit generates the Caller-ID information and
sends it on to a station phone, so we need to verify we are sending the
correct signals. (I don't want to test a Caller-ID phone for receiving
properly, per SR-
Ever hear of the Stealth Bomber? Same idea.
Daniel W. Mitchell
Product Safety
EOS Corp.
--
From: Robert Bonsen[SMTP:rbon...@orionscientific.com]
Sent: Friday, November 13, 1998 8:03 AM
To: emc-p...@majordomo.ieee.org
Subject:Re: ANSI C63.4-- OATS construction issues
I th
Related to the issue of reflections on an OATS is contaminants. I have
heard from a few sites that have all weather test capabilities, that they
need to periodically pressure clean their shelters -- 6 dB was suggested as
a variation due to contaminants. If the effects of contaminants apply to
she
Hi all,
I have received no responses to the original e-mail copied below. This in
itself is rather interesting and I would like to know why, so if any of you
have opinions on this, I'd like to hear them. My assumption is that there
have been no responses for one or more of the following reasons:
I would say this assumption is basically correct. The most sensitive
area of the cable is that adjacent and parallel to the antenna. In the
case of a bicon this is about the top 1m or so. Ferrite on the top
horizontal section would only be of benefit if the antenna is not
perfect, so a couple cl
The ferrites "remove" the cable from the fields to some degree. No matter
how perfect the baluns are the cable still represents a conductor out in
the middle fo the fields you're working with.
- Robert -
On Thu, 12 Nov 1998, WOODS, RICHARD wrote:
> Hans,
When attaching the Ferrites, do they need only be attached to the Vertical
portion of the cable? Assuming the common mode currents force the cable to
become an active element in the "system", then it would stand to reason that
the portion of the cable running across the Mast mounting bar (perpe
Imbalance may not be entirely due to an antenna. For example, a site I used
in Fountain Valley, California, had a lot of FM broadcast intermod while
using a 200-1000 MHz LP. Ferrites on the feed line fixed that; the antenna
did not reject common-mode 100 MHz energy on the coax shield, which was
th
Gent's
Scientific-Atlanta has build dish antennas with this type of
construction. The idea was the same, to lessen the transition on the
edge of the dish. The idea never made it into production. The
cost/benefit was not that great.
My approach is to o
I think a few sites exist having serrations like that. Typically shaped
with a cosine taper or triangular, with a spatial distribution which is
optimized to minimize edge reflections. Interesting concept that has been
used in a wide variety of applications to eliminate edge reflections caused
by an
We have a second story, weather protected 3m site. Ground plane measures
6.1m x 7.3m. NSA measurements always were close to the 4 dB limit at 30MHz
in horizontal polarization, all higher frequencies had no problems in
vertical or horizontal polarizations. The 30MHz trouble was attributed to
margi
This is an interesting discussion for all who operate a lab. I will like to
inject that I
have observed that about 1/3 of EMI labs are using ferrites at the base of
the
antenna connection. This is based on having visited more than 30 labs on 3
continents during the last 15 years. The reasons gi
Try
http://www.conformity.com
> --
> From:
> randall.flind...@emulex.com[SMTP:randall.flind...@emulex.com] on behalf of
> Flinders, Randall[SMTP:randall.flind...@emulex.com]
> Reply To: Flinders, Randall
> Sent: Thursday, November 12, 1998 4:11 PM
> To: 'emc-pstc'
> Subject:
Concerning the discussions on the use of ferrite loaded feed cables
during NSA (or any other measurements). There have been a number of
useful replies already but I would like to add a bit more information
for your consideration.
Using a feed cable which is co-polarized with the antenna will res
I think I know why your having trouble if its the "Conformity" that I think you
are referring to. Outside of Boston the area codes have changed as of 1/1/98 in
many parts of Massachusetts. Our wonderful (not) phone company in this part of
world allowed a very short period of time in which they
Here is what I got...
Phone: 978-486-0888
Fax 978-486-8828
Email: lbn10...@world.std.com
WEB: //world.std.com/~csweb/conformity.html
Good Luck
> -Original Message-
> From: randall.flind...@emulex.com [SMTP:randall.flind...@emulex.com]
> Sent: Thursday, November 12, 1998 4:12 PM
> To: 'e
Randy:
Lorie Nichols can be contacted at (978) 486-0888.
Also, you can try m...@conformity.com
http://www.conformity.com
Regards,
John R. Kretsch, P.E.
Compliance Engineering Supervisor
ADC Broadband Communications
john_kret...@adc.com
> -Original Message-
> From: randall.flind...@emul
Hello,
Looking at the discussion, i've thought that would be interesting if
someone who has an OATS which is operational put some photos of his open
site, it would help the discussion. What do you think?
Muriel
hmellb...@aol.com wrote:
>
> A1. Since concrete is partly conductive and varies with
Derek
As a father of one little girl (hope she won't be the only), I must say
I don't like things like this to be taken nonchalant. I leave that role
to the people that don't care. If we, who chose to work for safety,
don't care, who will? I just don't like to see lasers as toys in
children's hand
Jean-Marie,
This is the information that I have (current as of April this year, it
may be different now!)
The agency in Slovakia responsible for EMC is EVTU. EMC is mandatory,
the applicable standard is EN55022. Apparently additional testing is
required even if the equipment is already CE marked, b
Jean-Marie,
After sending the first reply I had another check. In the latest copy of
Approval magazine there is an article about Eastern European Telecoms
Approvals. The author is a Mark Boughen from KTL. He may or may not be
able to help you. His email address is mboug...@ktl.com Might be worth a
hmellb...@aol.com wrote:
>
> The ferrite loaded mast cable is obviously there for common mode rejection. As
> such, the CM can only be sourced form unbalanced baluns at the antenna, or
> from the imbalanced complex impedance variance caused from the mutual
> inductance of the antenae over the gr
Chaps,
I recall an interesting paper where the ground plane edge did not end
abruptly, but was shaped with what looked like petals. The work was also
stretched to cover dish antennas etc. For some reason the idea came from
Georgia springs to mind.
The paper claimed better performance from a small
First of all, expanding the width is a Good Idea. Generally speaking, the
larger the ground plane, the better it will approach a "perfect OATS" and,
hence, deliver better performance. This is particularly important for a
smaller sized OATS.
The minimal size described in CISPR22 is 1m beyond the b
Richard,
Re the ferrites during NSA measurements (and others): I was under the
impression that the ferrites prevented the shield of the vertically hanging
cable from becoming an additional (and unwanted) reflector element.In
making some NSA measurements I found adding ferrites to the hanging p
How about the converse, are there reasons not to put the ferrites on? Using
this example and assuming I had a balanced bicon so didn't need the
ferrites. If I put on a log periodic would I have to put ferrites on for
that?
If there is no drawback to the ferrites, then it seems that it would be
prud
IEEE EMC SOCIETY
ROCKY MOUNTAIN CHAPTER
DECEMBER MEETING
TUESDAY DECEMBER 8, 1998
VENDOR NIGHT
&
1999 CHAPTER OFFICIERS ELECTION
WHERE:
Raintree Plaza Hotel
1900 Ken Pratt Blvd.
Longmont, Colorado 80501
Phone: 303-776-2000
Silverthorn Room
1850 Industrial Circle
Longmont, Colora
Greetings Compliance Professionals!
The Orange County Chapter of the IEEE EMC Society is holding it's bi-monthly
meeting in Costa Mesa on Thursday, December 10th. A description of the
Technical presentation and the Speakers is given below.
The meeting will be held at Emulex Corporation, locate
For those curious about the health effects of laser light (or damage
caused by) or who want a pretty good explanation of laser classes and
other issues might try the Laser Institute of America web site. Their
address is:
http://www.laserinstitute.org/ for the home page and
http://www.laserin
Joe Hello,
For labelling, I would try to as much as possible use symbols,
such as those specified in EN61010-1 and IEC 417. Such symbols
should be explained in the manual and accompanied with the
cautionary statements.
Please note that equipment intended for lab use is most likely to
be used
The ferrite loaded mast cable is obviously there for common mode rejection. As
such, the CM can only be sourced form unbalanced baluns at the antenna, or
from the imbalanced complex impedance variance caused from the mutual
inductance of the antenae over the ground plane.
An antenna expert such as
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