[Linux-ham] [Fwd: [nc-triangle-ham-radio] 2nd interference
complaint - Progress Energy Phase II BPL]
Rob Rousseau KI4BKE
KI4BKE at nc.rr.com
Mon Mar 29 13:54:26 EST 2004
For those of you following the BPL issue...
My own opinion is that BPL will continue despite ARRL opposition.
Broadband to every house via plain powerlines seems like the Holy Grail
to power companies and politicians alike.
On a side note, I have a IBM Thinkpad 600E that I'd like to install
either Mandrake or some other flavor and devote it to HAM-radio programs
for the field. I can bring it to RARSFest.
-Rob Rousseau, KI4BKE
To: Len Anthony, Progress Energy Regulatory Affairs
From: Gary Pearce KN4AQ
116 Waterfall Ct.
Cary, NC 27513
kn4aq at arrl.net
Bill Godwin, Progress Energy
Anh Wride, FCC
James R.Burtle, FCC
Riley Hollingsworth, FCC (FYI)
Ed Hare, ARRL
Frank A. Lynch, ARRL
Monday, March 29, 2004
This e-mail letter is a second formal complaint of interference received
from several Broadband over Power Line (BPL) installations operated by
Progress Energy in the Wake County, North Carolina area. This complaint
covers interference on NEW frequencies that was not present in my first
complaint filed on March 13th.
In my March 13th complaint I detailed interference that I observed while
operating my mobile amateur radio equipment in the vicinity of the Progress
Energy Phase II BPL trial areas in southern Wake County, North
Carolina. No one from either Progress Energy or the FCC has contacted me
as a result of that complaint (except a request from the FCC to drop David
Solomon from the recipient list, which I have done). I have seen Bill
Godwin in a somewhat chance encounter at the Holland Church site, and we
had a good discussion on the state of the trial.
I have observed that Progress Energy has changed the spectrum used for the
overhead line segments in both trial areas. If I'm correctly assuming that
this was done to respond to complaints, and demonstrate frequency agility
and the ability to mitigate interference by avoiding amateur radio
spectrum, the attempt is appreciated, but it was not completely
successful. New amateur radio and shortwave spectrum is now receiving
interference, and that is the basis of this complaint.
On March 20, 2004, in the Woodchase subdivision area near Fuquay-Varina,
where BPL signals had covered the 12 and 10 meter bands, I observed clear,
strong BPL signature signals from 21.5 to 24.90 MHz, and 25.49 to 28.0
MHz. This almost cleared amateur radio spectrum, but not quite.
The lower segment, from 21.50 to 24.90 MHz, encroached clearly on the
bottom 10 kHz of the 12 meter band, from 24.89 to 24.90 MHz, and what I'll
call "residual" BPL carriers - carriers at the edge of the main spectrum
that trail off in amplitude over the course of 10 to 20 kHz - encroached
further. The residual carriers present a correspondingly decreasing
problem of interference, but when the bulk of the BPL carriers are strong,
the residual carriers can also interfere with weak amateur radio signals.
Note that if a BPL operator is attempting to place a BPL block adjacent to
the bottom of an amateur band, they should be aware that these residual
carriers will fall across an area of extreme interest where amateurs use
Morse code to communicate with distant, often very weak, amateurs in remote
parts of the globe. Additional care should be taken to avoid letting this
"residual" interference cross the bottom few kHz of any amateur band.
The higher segment, from 25.49 to 28.0 MHz, also left some residual
carriers encroaching on the bottom of the 10 meter band at 28 MHz. The
main carriers did cover all 40 CB channels and interfered with signals I
Then I drove through the Holland Church Road trial site and observed no
change since my March 13th complaint - the BPL signals still covered the 12
and 10 meter ham bands and adjacent spectrum.
On March 23, 2004, I returned to the Holland Church Road trial
area. That's when I ran into Bill Godwin and two other Progress Energy
engineers, observing and reporting on some difficulty that Amperion was
having moving the spectrum on the overhead line. The signals were gone
from the 12 and 10 meter bands, and appeared erratically elsewhere. Since
this was an effort in progress, I didn't worry about the signals I received.
On March 28, 2004, I returned to the Holland Church site again. This time
I monitored signals on the following spectrum blocks:
14.29 - 16.805 MHz
17.33 - 21.00 MHz
24.53 - 28.00 MHz (with 12 meter notch?)
Reception was somewhat difficult because of a high general noise level
(what we usually refer to as "power line noise," ironically in this
case. The true source of this particular noise is unknown). The BPL
signature signals were generally strong and clear above this noise.
After observing what appeared to be an attempt to completely avoid amateur
radio spectrum at the Woodchase trial area, I was disappointed to see that
two busy amateur radio bands were partially or fully covered here: 20 and
17 meters. The BPL carriers interfered with many signals as I tuned from
14.29 to the band-edge of 14.35 MHz in the 20 meter band. Strong signals
were audible, but BPL carriers placed a loud "beat note" behind them,
making reception irritating at best. Weaker signals were rendered unreadable.
I had the same situation across the entire 17 meter band, from 18.068 to
18.168 MHz. Weaker signals were impossible to receive, while stronger ones
were accompanied by a loud heterodyne whistle.
I also tried listening to some shortwave broadcast signals in the spectrum
immediately above the 20 meter ham band. Switching to AM reception with a
6 kHz band pass filter, I noticed that the BPL signals were a continuos
"blanket" across the spectrum. Since the BPL carriers were 1.1 kHz apart,
I heard the expected 1.1 kHz heterodyne tone as part of that interference
The 15 MHz signal from WWV was completely inaudible. Stronger shortwave
signals were audible with varying degrees of interference. Weaker signals
on 15.160, 15.205, 15.300, and 15.350 MHz were detectable but not
readable. This was just a brief sample of the many shortwave signals that
received interference from the BPL energy.
I could not observe any "residual" carriers spilling into the 15 meter ham
band as the "power line noise" made it difficult to hear the weakest BPL
carriers. With some difficulty I observed what appeared to be a notch in
the 24.53 - 28.0 MHz block. The carriers were at least attenuated in the
24.89 - 24.99 MHz area (the 12 meter ham band), but I thought I could hear
some weaker carriers through the "power line noise".
That is my report. I'll repeat my contention from my first complaint that
interference reports from mobile stations are warranted because:
- amateur radio is a very mobile radio service,
- these are very limited trial areas, and the experience and results must
be extrapolated to predict the effect BPL will have if widely deployed in
densely populated areas.
I'll conclude with an example of truly random interference caused by BPL to
a mobile ham who was not part of, or recruited by, our investigation team:
Over the past few weeks I've had an e-mail exchange with Andy Stoy K4MTN,
from Wake Forest, NC. Initially, Andy's e-mail sounded like many that Tom
Brown N4TAB, Frank Lynch W4FAL and I have received from area hams who
suspect that they are hearing BPL interference from areas where none is
known to exist. Andy said he had been hearing loud interference - he
called it "static" - for months along a half-mile stretch of Falls of the
Neuse Road near the Woodfield subdivision. He was describing the Phase I
trial area which we believed to have been disconnected, and his description
of "static" didn't sound like the BPL signature we're used to.
I pressed him for more specific details, and he finally described the exact
location, and the signature sound (closer-spaced carriers with a clicking
sound) of Amperion's BPL. Tom Brown traveled to the site and confirmed
that the Phase I equipment was still operating on the overhead line along
Falls of the Neuse Rd. Andy traveled that route daily, and regularly
operates on the 10 meter band. He had been receiving interference and loss
of communications on that stretch of road since at least last fall, but
didn't know what caused the problem until we began publicizing the
trials. Then he contacted us. He will be filing his own report of
Andy's story may seem isolated, a rare, chance occurrence. It is
significant for several reasons. One is that it happened at all, since
there is a total of less than two miles of BPL coverage along Wake County
highways. Another is that hams don't know what BPL is yet. We've reached
a few with our message, but many more have never heard of it. So there may
be a few more Andy Stoy's out there who have passed through the existing
trials areas, received interference, and didn't know what it was or who to
I appreciate the fact that Progress Energy and Amperion are responding to
our reports and complaints of interference. I'd prefer to just call them
"reports," but public proclamations that "there have been no interference
complaints" have pushed us to this formal posture. My goal is to make you
(Progress Energy and the FCC) aware of the real conditions for radio
amateurs and other HF spectrum users in the trial area so that you can
anticipate the level of difficulty you can expect in a broader implementation.
I'd expect that Progress Energy and Amperion could completely avoid amateur
radio spectrum in the overhead segments of this limited trial area. I'm
surprised that after the first complaints, you moved to occupy different
amateur radio spectrum. But even if you had completely missed ham bands in
this first move, success in this limited arena is not a good predictor of
the ability to mitigate interference in a full system, where you will be
constrained to use more spectrum and not re-use spectrum for several line
segments. And the question of interference from the underground line
segments has not been addressed at all.
Gary Pearce KN4AQ
================ KN4AQ's March 13, 2004 complaint, for reference
I encountered all of this interference while mobile, or visiting the
stations of other amateur radio operators. I do not hear any BPL
interference at my home in Cary at this time.
November 16, 2003. I first encountered BPL interference on this date, near
the Wakefield subdivision in north Raleigh, along Falls of the Neuse Road
near Wakefield Pines Rd. The interference appeared as a series of closely
spaced RF carriers, approximately 1 kHz apart, covering the lower half of
the 10 meter amateur radio band, from 28 to near 29 MHz (and some spectrum
below that band, including the 40 CB radio channels near 27 MHz). Some of
the carriers had a little "tik-tik-tik" sound at about a 2 Hz rate. The
interference was strong - S-9 - for about a half mile along Falls of the
Neuse Road, and obliterated several amateur radio signals that I was
I understand this was the Phase I trial area, and the test has been
January 15, 2004. On this and several subsequent dates, I received
interference while driving along Holland Church road between 1010 Road and
Pagan Rd. in southern Wake County, specifically in the vicinity of Feldman
Dr. The signature of the interference was the same: closely spaced
carriers, about 1 kHz apart, some with a tik-tik-tik modulation, and
occasionally a longer burst of what sounded like data. The interference
covered two blocks of spectrum, from 23.44 - 26.08 MHz (including the
amateur radio 12 meter band) and 27.9 - 31.7 MHz, (including the amateur
radio 10 meter band). The interference was strong - S-9 - for about a half
mile along Holland Church road, and audible in places along Pagan Rd. It
obliterated several amateur radio signals that I was monitoring as I drove
through the area.
I also received interference with the same signature in several spots along
Feldman Dr., in various other segments of the high-frequency spectrum -
near 11 and 15 MHz in particular. The signals were weaker, but plainly
audible. Onc caused a "beat note" against the 15 MHz WWV time and
frequency reference signal.
I have subsequently been through this area several times, and the
interference is still present. My last visit was on February 28th.
February 20, 2004. On this and several subsequent dates, I received
interference while driving along NC Highway 55 and James Slaughter Rd, just
north of the town of Fuquay-Varina. The interference was strongest along
James Slaughter Road, opposite the Woodchase subdivision. Again, the
signature of the interference was RF carriers, about 1 kHz apart, with a
bit of digital modulation now and then, including the tik-tik-tik at about
a 2 Hz rate.
This interference was across 21.9-25.7 MHz (including the amateur radio 12
meter band) and 27.5-30.0 MHz (including the amateur radio 10 meter
band). The interference was S-9 along James Slaughter Road, and S-5 in the
Food Lion parking lot at NC-55, and obliterated several amateur radio
signals that I was monitoring.
In the Woodchase subdivision, I also heard the "BPL signature" signals on
several other points in the high frequency spectrum. The signals were
weaker, but plainly audible. I also heard signals in the 7 and 24.5 MHz
area about a mile further north on James Slaughter Road, near the
Whitehurst subdivision. These signals were S-6 to S-9 for about 1/4 mile
along James Slaughter Road.
I most recently heard this interference on March 5th, 2004.
Finally, on February 28, 2004, I personally visited the homes of three
amateur radio operators who live in the vicinity of the Progress Energy
Phase II BPL trials, and observed interference as received at their
stations as follows:
Mike Payne KM4UT
5813 HEATHILL CT
Mile lives .7 miles south of the trial site on Holland Church Road. He is
using a dipole antenna at about 30 feet. I observed that he was receiving
a clear but weak BPL "signature" in the top half of the 10 meter band,
above 28.8 MHz, and many smaller clusters of individual carriers in the
band below that.
Ted Root N1UJ
509 WYNDHAM DR
Ted is about a half mile southwest of the James Slaughter Road site. He is
also using a dipole antenna at about 40 feet. He was receiving weak but
clear BPL signature signals across the 25 and 28 MHz areas.
Roland Erickson WA0AFW
201 WILBON ROAD 301B
Roland is about a half mile south of the James Slaughter Rd. site. He is
using a dipole antenna in the attic of a retirement village building. He
has a very high ambient noise level (S-6) across the 25 and 28 MHz bands,
but was receiving the BPL signature signals clearly above that noise level
across those bands.
You might ask if my complaint of interference while mobile, some distance
from my home, is justified. I contend that it is, for several reasons.
First, amateur radio is a very "mobile" service. Tens of thousands of
amateur radio operators have and use high frequency mobile equipment, and
we can be found anywhere, using all hf bands, at completely unpredictable
Second, the Progress Energy Phase II trials are in very limited area
tests. There are no amateur radio operators living inside the
neighborhoods being served, though there are several within interference
range - about a mile. We are justified in traveling to the sites with
normal amateur radio equipment, operated in a normal manner, to observe and
complain about interference we receive. This observation must be
extrapolated to a wider geographic area to anticipate the kind of
interference that would be received if BPL were to be widely deployed,
especially in denser suburban and urban neighborhoods.
You might also ask if weak BPL signals constitute harmful interference. I
contend that they do. Amateur radio operation is unlike most other radio
operation, in that amateurs tune across their band segments looking for
signals. Often we are looking for weak signals from distant parts of the
world. Our predominant modes are single sideband and cw. In those modes,
a series of carriers 1 kHz apart presents a most irritating series of "beat
notes" - tones that vary in pitch as the spectrum is tuned. At 1 kHz
spacing, they are continuously present in a receiver using customary
bandwidth filters. And even weak BPL signals can make weak amateur radio
signals difficult or impossible to receive.
The presence of any BPL signal of any strength at either a home or mobile
station at any location is an unwarranted incursion in the amateur radio
bands, and is also a problem for anyone tuning shortwave broadcast or other
Thanks for your consideration. I look forward to hearing the results of
the investigation into my complaints.
Gary Pearce KN4AQ
Gary Pearce KN4AQ editor, SERA Repeater Journal
Cary, NC www.sera.org
919-380-9944 kn4aq at sera.org
kn4aq at arrl.net
AOL/Yahoo Instant Messanger: KN4AQ
(send e-mail to be put on my "buddy list")
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