I have thought of a few more points to add. In test area #1, the system is
"HomePlug" notched. This system has little energy in the ham bands, except for
the new allocation at 5.3 MHz. In that area, what Mike is characterizing as
"sparking" was loud and clear outside the ham bands, and on 5.3 MHz, but just
audible inside the ham bands on the antennas used for testing. This would not
occur with sparking. What was heard matched the HomePlug specification
perfectly.
In test site #3, we heard the signals over a wide frequency range, but, if
memory serves, right at the edges, we could hear the signals drop off sharply
over a few hundred kHz range, and in that in-between range, the very nature of
the noise changed, become a bit more erratic. I will have to look at my video
roll again to see if I got that on tape. This, too, would not occur with
sparking.
What is apparently needed is a spectrum analyzer plot of the noise, showing how
it varies with frequency in a way that sparking could not vary and a
time-domain plot, showing the bursts that are not at all like what is found
from power-line sparking. I will be sure to gather that data on my next visit
to the trial areas.
That is the value of dissenting opinion on these discussion forums, because
from that, specific deficiencies can be discussed and improved. From some of
the concerns raised by the amateur community, I have been able to make
improvements in ARRL's presentation, and this is no exception.
Mike Martin truly does have the interests in amateur radio at heart in all he
does, as do I, so if we disagree, we should always remember that those with
different views than ours do may mean just as well as we do. Mike has been a
strong ally in the general area of power-line noise and will continue to be
such with ARRL no matter what his views on BPL. People can disagree on one
point and still have common ground on others, and without Mike Martin, ARRL's
work on power-line interference would be a lot harder and a bit less
successful.
73,
Ed Hare, W1RFI
ARRL Lab
225 Main St
Newington, CT 06111
Tel: 860-594-0318
Internet: w1rfi@arrl.org
Web: http://www.arrl.org/tis
> -----Original Message-----
> From: Hare,Ed, W1RFI
> Sent: Monday, August 11, 2003 5:02 PM
> To: rfi@contesting.com
> Subject: RE: [RFI] RE: Concerning BPL video
>
>
> > Well, it's obvious from the BPL video that BPL is indeed
> needed. I say
> > this because of the bandwidth that is used up by all the unjustified
> > negative publicity concerning BPL. After listening to the
> > audio several
> > times, I hear nothing that sounds like BPL. I'm a little
> > confused. Maybe
> > I down loaded the results of and interference complaint caused by a
> > combination of power line sparking and several narrow band
> > inside noise
> > sources. I'll listen again.
>
> Do I presume you have downloaded the ARRL video? Those
> "several narrowband inside noise sources" seen in test area
> #4 are better desrcribed as "several hundred." Those birdies
> are spaced about every kHz, for several MHz at a time, heard
> for miles down any line carrying the BPL signal.
>
> 73,
> Ed Hare, W1RFI
> ARRL Lab
> 225 Main St
> Newington, CT 06111
> Tel: 860-594-0318
> Internet: w1rfi@arrl.org
> Web: http://www.arrl.org/tis
>
>
>
> > -----Original Message-----
> > From: Mike @ RFI Services [mailto:mike@rfiservices.com]
> > Sent: Saturday, August 09, 2003 12:20 PM
> > To: rfi@contesting.com
> > Subject: [RFI] RE: Concerning BPL video
> >
> >
> > Well, it's obvious from the BPL video that BPL is indeed
> needed. I say
> > this because of the bandwidth that is used up by all the unjustified
> > negative publicity concerning BPL. After listening to the
> > audio several
> > times, I hear nothing that sounds like BPL. I'm a little
> > confused. Maybe
> > I down loaded the results of and interference complaint caused by a
> > combination of power line sparking and several narrow band
> > inside noise
> > sources. I'll listen again.
> > Question:
> > Has anyone ever heard of a complaint filed by a ham that is
> > experiencing
> > RI from BPL? I have. The source was a touch control lamp 2
> > blocks away.
> > With an active BPL system in the QTH.
> > I'm in the business of locating the sources of RFI,
> regardless of the
> > cause(s). So if BPL were a problem, it could be seen as
> another source
> > of job security for me. However, to this date I haven't heard
> > of another
> > complaint made by a ham claiming to have problems from BPL. Why?
> > Has anyone else seen a complaint that the cause was found
> to be BPL?
> > Of all the concerns we read about on reflectors, why are they all
> > responses to the concerns and never about a known problem? Surely
> > someone would have had one by now. These test systems are in
> > areas that
> > know one even knows about. Still no complaints. After everyone is
> > notified that the system is under test and it is offered, still no
> > complaints. Why?
> > When I'm testing for BPL emissions, I can hear it while my
> > antenna is 20
> > feet from the source. However, when I drive away the signal is gone.
> > Why don't we put this much energy into stricter enforcement
> concerning
> > Dimmers, touch control lamps, doorbell transformers,
> aquarium heaters,
> > power supplies, TV sets and telephones. This would be a real
> > challenge.
> > I investigate over 500 RFI complaints per year and over 60%
> > of them are
> > the sources listed above. Their are more but they are the
> > most frequent.
> > Power line carrier systems have been in houses and on power
> lines for
> > the entire 25 years I've been involved in RFI. I can count the
> > complaints concerning them on one hand. Those systems didn't
> > bypass the
> > ham bands as do the new systems.
> > The questions I'm asking above are not because I'm looking
> > for answers.
> > They are questions you should ask yourself.
> > I think I already know the answers.
> > Very sincerely Best wishes,
> > Mike Martin
> > RFI Services
> > 6469 Old Solomons Island Rd
> > Tracy's Landing MD 20779
> > 301-855-5961 Tel (E.S.T.)
> > 410-741-5153 Fax
> > 164*21*29180 Nextel
> > mike@rfiservices.com
> > www.rfiservices.com
> >
> >
> >
> >
> > _______________________________________________
> > RFI mailing list
> > RFI@contesting.com
> > http://lists.contesting.com/mailman/listinfo/rfi
> >
>
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