Pat:
Almost every military product that I test needs support equipment to make it
function. I may have to create external signals, monitor operation, send
commands, log data or command other support equipment. Laptops have become the
controller of choice for exercising the military hardware during development
and test phases.
The laptops are not just running software, they are intimately (for me,
usually way too intimately) connected to the military hardware by USB,
Ethernet and serial busses. Even worse, the laptop is usually placed right
next to a big collection of commercial test equipment (spectrum / modulation /
network analyzers, power supplies, signal sources), consumer media equipment
(we use video discs to stream dummy data through the military hardware) and a
junkbox of non-deliverable switchboxes, hubs, patch cords and blinky lights.
You see, I'm not testing the laptops, but they are electrically present in my
real test environment. I want the laptops to be as quiet as possible, and as
immune as possible. OTOH, I have to work with what a program brings me, and
the programs don't really ask me about which laptops to buy. And, as our
discussion has shown, there is no publicly available data about EMC quality
for typical commercial laptops. It's great that an "insider" speaks up to
offer help, but my point was about availability of data and how that might
affect a buyer's choice.
Getting back to my own preferences, I suppose it's a question of how good is
good enough? I'm always looking to use less lossy coax, or find a microwave
pre-amp with a 0.7 dB noise figure. If I was selecting a laptop for my lab, or
recommending one, I would like to be able to choose the best EMC performance I
could find (and afford). Of course I recognize that I represent a very small
and stingy market, so I don't expect laptop manufacturers to worry too much
about me.
However, I still would like to be able to see compliance data, not just a
statement, at a manufacturer's site. Some manufacturers do things just for
good customer relations, or brand image. For instance, Agilent maintains a
site where you can download service manuals for many totally obsolete HP
equipments. A company that thinks like that may just well see the value in
showing the real EMC performance of their products.
Hint! <g>
Ed Price
[email protected] <blocked::mailto:[email protected]> WB6WSN
NARTE Certified EMC Engineer
Electromagnetic Compatibility Lab
Cubic Defense Applications
San Diego, CA USA
858-505-2780
Military & Avionics EMC Is Our Specialty
________________________________
From: Conway, Patrick R (bNB Houston) [mailto:[email protected]]
Sent: Wednesday, April 22, 2009 7:27 AM
To: [email protected]; 'E. Robert Bonsen'
Cc: 'Brent G DeWitt'; Price, Edward; [email protected]
Subject: RE: [PSES] SV: "Quiet" Laptop
Last week I offered my “professional assistance” to help find quiet
laptops.
Now I will offer my (less) helpful “philosophical assistance”…
Is our community too close to this topic to see it
clearly?
Is it the “Can’t see the forest for the trees”
phenomena?
For instance- when was the last time we had a wide
spread EMC
problem in the consumer electronics community?
We all know of “little” problems, but when was the last
time there was a pervasive problem?
Our community, and the EMC Professionals that came
before us,
should take credit for this achievement.
Same goes for laptops-
They are designed, built and manufactured to run
software.
As an EMC professional I agree that there there is value in owning a
laptop
that never, ever looses it’s EMC performance.
But where do I buy one?
We build a good product (pick one), it performs to spec, and customers
are
happy.
We should be happy, but alas, we are too close to the topic. We know it
could perform better if only…
Best-
Patrick.
OOO- and for amusement purposes only!
-
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