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[RFI] RE: Concerning BPL video

To: <rfi@contesting.com>
Subject: [RFI] RE: Concerning BPL video
From: w1rfi at arrl.org (Hare,Ed, W1RFI)
Date: Mon Aug 11 17:49:11 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@arrl.org
Web: http://www.arrl.org/tis



> -----Original Message-----
> From: Hare,Ed, W1RFI 
> Sent: Monday, August 11, 2003 5:23 PM
> To: rfi@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@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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