Interesting observation. You said hum gets louder.
Implying hum is already there. What kind of phone?
Is it only that one telephone instrument?
Only occurs when LEDs are near the instrument, not near the
phone lines with the phone in another location?
Is the effect more pronounced at l
Hi all,
Actually I was using a good ole Spectrim Analyser
so I sidestepped the windowing issue/software issues
altogether.
What I was(am)trying to do was match the max voltage
as measured on a scope with the value as measured
on a SA.
I first calibrated myslef using a known source - a sine wave
Charles Grasso wrote:
>> What I was(am)trying to do was match the max voltage
as measured on a scope with the value as measured
on a SA. <<
Try zero span on the SA. Compare THAT with the scope.
Cortland
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc disc
I presented a paper on that very subject about a decade ago at one of the
EMC T&D magazine EMC symposia. I used a Fluke Scopemeter and some FFT
software that came with it. The Fluke interfaced to the PC through an
optically isolated RS-232 protocol. It worked quite well from a
pre-compliance or
Hi All,
Has anyone tried correlating the voltage ripple
as seen on a scope with the amplitudes measured
on a Spectrum Analyser?
I tried doing that the other day with ..umm. minimal
success. I think that due to the comples convoltions
that would have to occur when FFT'ing an irregular
voltage
List members,
What is the limitation on minimum pulse width in reverberation chambers? I
expect it relates to room size, but does anyone have either a functional
relation or a rough order of magnitude? Light travels 300 meters per
microsecond, so I would think a 1 microsecond pulse width would
You are making the same argument Mr. Woodgate did, but adding another
mechanism for creating the rf emission. Note that I did not offer an
explanation of the source of an rf emission, I simply postulated its
existence. Then I stated my point of departure from Mr. Woodgate's
analysis, which was t
I read in !emc-pstc that Ken Javor wrote
(in ) about 'self blinking
LEDs as EMI sources WAS: LED lamps' on Sat, 26 Jul 2003:
>I agree with most of Mr. Woodgate's commentary, but I wonder if the
>presence of even an rf emission (as contrasted to 50 Hz) should cause
>any problem to a land-line p
Ken Javor wrote:
>> ... but I wonder if the presence of even an rf emission (as contrasted
to 50 Hz) should cause any problem to a land-line phone with a wired
handset. It wouldn't seem likely that the
power available from a couple AA batteries would be sufficient for that.
Now if it were a co
I agree with most of Mr. Woodgate's commentary, but I wonder if the presence
of even an rf emission (as contrasted to 50 Hz) should cause any problem to
a land-line phone with a wired handset. It wouldn't seem likely that the
power available from a couple AA batteries would be sufficient for that
I read in !emc-pstc that Wan Juang Foo wrote (in
)
about 'self blinking LEDs as EMI sources WAS: LED lamps' on Sat, 26 Jul
2003:
> These circuits
>were found to (well at any rate, seems to) emit interference that cause
>a telephone to pick up (50Hz) hum!
Up to that point, your treatment of
Dear All,
I observe recently that some self blinking (and color changing) LEDs 'are'
what seem to be a substantial emitters of radiated emission/interference.
These LEDs are rigged up by hobbyists as decorative illuminators and acts
more or less like the blinking lights for Christmas trees. I obs
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