[RFI] RE: Concerning BPL video
Hare,Ed, W1RFI
w1rfi at arrl.org
Mon Aug 11 18:48:51 EDT 2003
> 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.
What PLC systems operate on amateur spectrum? I know of only one, and it serves as a good case history of what to expect. It, too, complied with the FCC limits, but operated on 3.53 MHz
http://www.arrl.org/tis/info/rfiteljx.html
73,
Ed Hare, W1RFI
ARRL Lab
225 Main St
Newington, CT 06111
Tel: 860-594-0318
Internet: w1rfi at arrl.org
Web: http://www.arrl.org/tis
> -----Original Message-----
> From: Hare,Ed, W1RFI
> Sent: Monday, August 11, 2003 5:23 PM
> To: rfi at contesting.com
> Subject: RE: [RFI] RE: Concerning BPL video
>
>
> 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 at arrl.org
> Web: http://www.arrl.org/tis
>
>
>
> > -----Original Message-----
> > From: Hare,Ed, W1RFI
> > Sent: Monday, August 11, 2003 5:02 PM
> > To: rfi at 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 at arrl.org
> > Web: http://www.arrl.org/tis
> >
> >
> >
> > > -----Original Message-----
> > > From: Mike @ RFI Services [mailto:mike at rfiservices.com]
> > > Sent: Saturday, August 09, 2003 12:20 PM
> > > To: rfi at 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 at rfiservices.com
> > > www.rfiservices.com
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > RFI mailing list
> > > RFI at contesting.com
> > > http://lists.contesting.com/mailman/listinfo/rfi
> > >
> >
>
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