Gentlemen,
Not only Ultrasound Imaging manufacturers should react:
The interference potential of a interference source
classically has been founded on several factors :
amplitude : regulated by conducted or radiated emission limits
frequency : basically no (radio) frequencies are exempted from limits but
for ISM equipment some equipment (radio) have enhanced or relaxed frequency
ranges.
Statistically the "chance" to be hit by interference is the common range
of interfering frequencies and the frequencies one is sensitive to
(received freq. in case of radio).
BPL annihilates one of these factors. By design, energy is spread
all over the spectrum to obtain a flat energy spectrum from
less then 1 up to 50 MHz.
The technique allows for slots in the spectrum to emit more of
less energy on certain frequencies.
The chance however to be "hit" now, is 100 %, and the only
factor that may impact interference is amplitude.
BPL is also a fundamental error in abusing RF-asymmetric lines
(power lines) as a transmission medium for RF signals.
This is against what I would call "good engineering practice",
where we try to match source , load, and transmission medium.
All electronic RF engineers MUST oppose against such misuse.
The proposal as mentioned does not include conductive measurements
on BPL output ports. Instead radiated measurements will be used.
The frequency spectrum below 30 MHz is not suitable for
radiated measurements due to the fact that one is always measuring
under close field conditions.
European experiences with BPL has shown substantial differences
in both measured levels and interference problems in BPL experiments
No consensus about which method and which limits to be used has been
achieved yet.
For now I want to call upon all of you to support " the battle
against BPL" by sending you reactions to the address mentioned in
this proposal, as it will definitely makes an end of the principle
of "efficient use of the spectrum".
Gert Gremmen
ce-test, qualified testing
From: [email protected]
[mailto:[email protected]] On Behalf Of Garnier, David S
(MED)
Sent: donderdag 4 maart 2004 20:51
To: [email protected]
Subject: Attention Ultrasound Imaging manufactures: Acuson, ATL, Philips, HP
and others...
Gentlemen,
Have you considered the FCC's "Notice of Proposed
Rule Making" for Broad Band over the Powerline (BPL)
a possible threat to your image quality? We are aware
that the modulation format is OFDM but we are interested
in hearing your thoughts on this subject.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-29A1.pdf
Please contact me off list.
Regards,
Dave Garnier
David Garnier
e GE Medical Systems
___________________________________________
David S. Garnier
Senior Technician
Functional & CT Engineering
3000 N. Grandview Ave - M/S W-1250
Waukesha, Wi. 53188
Tel: 262.312.7246
Cel: 414-899-7580 (NEW)
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Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ieee-pses.org/
To cancel your subscription, send mail to:
[email protected]
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Ron Pickard: [email protected]
Dave Heald: [email protected]
For policy questions, send mail to:
Richard Nute: [email protected]
Jim Bacher: [email protected]
All emc-pstc postings are archived and searchable on the web at:
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