Brian,
We have a 6dB 50 watt attenuator from Weinschel that is fairly compact. We use
a 90 degree N-N connector to join the attenuator to the clamp.
Bob R.
Kunde, Brian brian_ku...@lecotc.com wrote:
Bob,
Isn't the attenuator optional? I know it is a good idea because it helps to
match
In my limited experience, I have not performed or witnessed tests in
accordance with this std that actually let the UUT free-fall. For example,
note following excerpt from MIL-STD-810F:
2.2.2.5 Procedure V - Drop table.
Ballistic shock is simulated by the impact resulting from a drop. The test
We had turned off the modulation. Will carry on with the test setup
investigation tomorrow.
Thanks.
Best regards
Amund
-Opprinnelig melding-
Fra: emc-p...@ieee.org [mailto:emc-p...@ieee.org]På vegne av Javor
Sendt: 17. september 2007 17:01
Til: am...@westin-emission.no
Kopi:
Grace,
Are EMC test labs accredited to NVLAP or A2LA in China?
Cecil Gittens
From: Grace Lin graceli...@gmail.com
List-Post: emc-pstc@listserv.ieee.org
Date: Friday, August 10, 2007 12:29 pm
Subject: China CNCA 2007 Notice No. 21
To: emc-p...@ieee.org
To Those Who are Interested in:
Group
This may be a little off topic, but I know that some of the group are involved
in Environmental testing, or work closely with someone who is.
MIL-STD-810F 516.5 procedure IV defines height for drops and number of drops,
but I cannot see where it defines the surface onto which equipment
David,
That is not something I have really thought much about. However, we do use a
clamp with an EM shield (as most clamps have) and have a short braided ground
strap from the clamp to the ground plane. I would hope this would reduce some
of the effect you mention.
We have noticed that the
Brian,
I prefer running the test the way you describe, for better repeatability.
However, the standard test setup includes a 6dB attenuator at the input of the
EM clamp (or CDN) and the resulting increase in the return loss due to the
attenuator would tend to mask some of the effect of EUT
This appears to be an easy thing to verify with measurement, assuming
you have a receiver or SA for these bands...
It would be as simple as initiating a call between your
reference handset and a nearby cell site. Then using a (homemade?)
dipole and the SA, tune the SA to the correct band
Inserting a current clamp between the E-M clamp and EUT could give
misleading data. The radiated field is high near the EUT side of the
E-M clamp (check it with a field probe) due to impedance mismatch. Not
only does the clamp couple into the field, but it also disturbs the
field, introducing
Bob,
Can a directional coupler be used between the amp and the clamp to measure the
forward power during the calibration test, then with the clamp connected to
the EUT, re-level on your calibration points to match the forward power?
Would this compensate for the impedance difference in the EUT?
Look at the loop:
GND-PLANE -- AE CM-impedance -- Clamp -- EUT CM impedance GND-PLANE
It's a simple loop consisting of 2 resistors of 150 Ohm and a 10V (low
impedance) voltage
source in between.
If you look at the way the pre-set level for clamp testing is
calibrated,
you will notice that
The cell sites use circular polarization I believe. Some appear to linear
polarization at 45 degrees.
On 900 MHz the handset usually (always?) uses the bottom half of the phone
as the bottom half of a vertical dipole. The upper half of the dipole is the
stub antenna or a 90-degree whip. On 1900
Or standing up or lying down.
Bob Heller
3M EMC Laboratory, 76-1-01
St. Paul, MN 55107-1208
Tel: 651- 778-6336
Fax: 651-778-6252
=
John Woodgate
In message 002701c7f93a$5f2d1d40$260bb...@colorado.linear.com, dated
Mon, 17 Sep 2007, David Cuthbert dcuthb...@linear.com writes:
I have been told that cellular handsets transmit vertical polarization
in the 900 MHz band and horizontal in the 1900 MHz band. Is this
correct?
Surely it depends
In message 46ee8874.13b48c0a.236f.6...@mx.google.com, dated Mon, 17
Sep 2007, Scott Xe scott...@gmail.com writes:
Are you sure Off can be used for | and On for O? Are they
interchanged?
It's a JOKE. The circle with diagonal bar is the sign for 'not' or
'prohibited'. So the symbols mean 'not
In my earlier response, I assumed the measurement would be made with
modulation off.
The peak would be 5.1 dB higher with 80% modulation, but what is measured on
the spectrum analyzer would, as you point out, depend on the bandwidth
settings. For true RMS power meters, the measurement would be
Presumably you have the 80% modulation. If you use a spectrum analyzer
with peak detection and a bandwidth larger than the required
modulation bandwidth you will capture the peak of the modulation
envelope, which would be 120 mA. In dB, that is less than 1 dB error,
within the uncertainty
I have been told that cellular handsets transmit vertical polarization in the
900 MHz band and horizontal in the 1900 MHz band. Is this correct?
Dave Cuthbert
Linear Technology
__
This email has been scanned by the
Robert,
Are you sure Off can be used for | and On for O? Are they interchanged?
Regards,
Scott
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Robert Johnson
Sent: Monday, September 17, 2007 11:35 AM
To: emc-p...@ieee.org
Subject: Re: I O power switch
You may
Amund,
For the current to be that high, the impedance of the EUT and the AE would
both have to be very low. The EM clamp is designed to have some directivity,
but not at the lower frequencies, and never more than about 10dB through any
of the frequency range.
In a perfect 150 ohm system, with
When testing with EM clamp, the IEC/EN61000-4-6 gives a requirement
to not exceed Imax (e.g Imax = 10V / 150 ohm = 66mA).
We use a current clamp to measure on a 2-wire unscreened cable, and
it is placed between the EUT and EM clamp. The current is measured to
approximate 130mA.
The test lab say
Anders
EN 300 386 covers (non-radio) telecommunications network equipment. So radio
equipment and terminal equipment are not within its scope. Thus the equipment
within its scope is not within the scope of the RTTE Directive.
For RTTE EMC requirements, it was optional to use the
In the sense of the RTTE directive such equipment which is included of EN 300
386 its neither a telecom terminal equipment nor a radio. That is only
network equipment and therefore this standard is published under the EMC
directive.
That is my understanding.
Mit freundlichen Grüßen
Yours
In message 002401c7f914$3624ec00$154d4d0a@MmPc21, dated Mon, 17 Sep
2007, Piotr Galka piotr.ga...@micromade.pl writes:
So if the manufacturer has the authorised representative in the
Community and I wont to be an importer I have nothing to do with DoC
(even not see it, because it is
Dear experts,
I dont find the standard EN 300386 in the list for harmonised standards for
the RTTE directive, anyone who knows why?
I find it only in the standards harmonised for the EMC Directive.
(I have heard that you for products in the scope of the RTTE directive you
could not use the
John and Dennis,
Thank you for resetting my wrong assumptions.
Few years ago, when I was first time learning how CE marking works reading
something (?) I understood, that all legal actions for the out of EC
manufacturer must be done by his authorised representative in the Community.
I was
You may find the markings http://www.itesafety.com/switch.gif at
www.itesafety.com/switch.gif acceptable for single pole switches ;^)
Bob Johnson
John Woodgate wrote:
In message mailto:46ebb5ba.1a36720a.105a.f...@mx.google.com
46ebb5ba.1a36720a.105a.f...@mx.google.com, dated Sat, 15
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