Good point. Ed, what does a plasma TV look like compared to BPL. Is the
multidomain signature quite different?

I have not looked at a plasma TV, Chip, but I would make that diagnosis
primarily on on the basis of the sphere of influence. In the BPL test areas,
the interference was heard over the entire area that had the BPL couplers in
place.

There are other indicators, too. Knowing the involved BPL manufacturer would
let one pretty easily compare what was heard on the air to the known
characteristics of the BPL system involved. Interference from plasma TVs is
not
going to be "modulated" with digital signals, as would a BPL signal. Those
OFDM carriers in the Ambient and Amperion BPL systems would be pretty hard to
confuse with anything else.

Another characteristic to look for is spectral occupancy. If the signal
appears
suddenly in spectrum, is heard over several MHz, then suddenly tapers off,
that
also matches the BPL characteristics, not that from other devices.

If the signal is noiselike, but clearly digital in sound, one can also look
for
the bursts of the downloads, followed by the shorter, "keep alive" pulses
that
some of the systems do.

If all of the above added up and started at the same time the BPL system was
brought on line, I would feel comfortable with my diagnosis.

73,
Ed Hare, W1RF


Hi Ed,

I think a general description of other RFI sources would be helpful for any
radio amateur to make a 'first cut' assessment. It might also help you isolate
the truly legitimate cases of BPL RFI--if and when they exist.

I do have a concern that hams not make too many false alarms. Sounds like you
are on top of the the problem and I wish you the best.

73,
Chip N1IR

Ed...

Is the ARRL preparing a FAQ for amateurs who have scopes, spectrum
analyzers, or service monitors, etc., as to how they might go about
inspecting a suspected chunk of spectrum and how detect, identify,
qualify whey they see/hear?

73
Dan (K0DAN)

I have not looked at a plasma TV, Chip, but I would make that diagnosis
primarily on on the basis of the sphere of influence. In the BPL test areas,
the interference was heard over the entire area that had the BPL couplers in
place.

There are other indicators, too. Knowing the involved BPL manufacturer would
let one pretty easily compare what was heard on the air to the known
characteristics of the BPL system involved. Interference from plasma TVs is not
going to be "modulated" with digital signals, as would a BPL signal. Those
OFDM carriers in the Ambient and Amperion BPL systems would be pretty hard to
confuse with anything else.

Another characteristic to look for is spectral occupancy. If the signal appears
suddenly in spectrum, is heard over several MHz, then suddenly tapers off, that
also matches the BPL characteristics, not that from other devices.

If the signal is noiselike, but clearly digital in sound, one can also look for
the bursts of the downloads, followed by the shorter, "keep alive" pulses that
some of the systems do.

If all of the above added up and started at the same time the BPL system was
brought on line, I would feel comfortable with my diagnosis.

73,
Ed Hare, W1RF

Carl R. Stevenson wrote:




S9+10 on a VERY short whip (an "Outbacker Joey") is a pretty huge
signal to me ... with BPL proposing to go up to 80 MHz, I would
think that the FM broadcast band is at relatively low risk, though FM
receivers could experience some degree of "desense" if the BPL
signal at the front end was strong enough due to proximity.

TV channels 2, 3, 4, and 5 will get clobbered by the junk going up to 80MHz.
The video signal is AM modulated onto the channel carrier (with a
portion of the
lower sideband suppressed) and will have no ability to reject the BPL
noise.
The effect would be somewhat similar to a sparky vacuum cleaner motor
throwing
white and black spots throuout the picture. The sound, being FM, will fare
better. Well, there's digital HDTV, but most everyone still uses analog TV.
And I don't get cable or satellite.

Mike Coslo wrote in message .net...
James Wilson wrote:
What does BPL sound like? Can someone post a wav file somewhere so it can
be identified? Is it worse that the Pennsylvania QSO party?

Did someone take over a frequency you owned?

- Mike KB3EIA -

Mike, that was kinda rude.

On Wed, 15 Oct 2003 20:20:31 GMT, "Jim Hampton"
wrote:

Brian,

I don't know about you, but I received a whole week pass from Belleveu
I'm not sure about the crazy part, but...
For those who have a "good" broadband connection here is a panoramic
view from the top of my tower. If you don't have broad band, don't
waste your time. This thing is 19.5 megs. It should take under a
minute with cable, and close to 10 minutes with ADSL, so you can
imagine how long it'd take with a dial up connection.
http://www.rogerhalstead.com/towerview.htm
I stood on the triangular top plate of the ROHN 45 G (at 100 feet) and
shot the entire series hand held. The camera was set to manual, but
the wind was gusting to 20 MPH plus, so a few of them didn't line up
good enough for a proper match when making the panorama.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

"Jim Hampton" wrote in message ...
Brian,

I don't know about you, but I received a whole week pass from Belleveu

73 from Rochester, NY
Jim AA2QA


So you got three hots and a cot AND a weeks pass (all paid) and the
rest of us have to learn it because you had to do it?

That's not the way it works anymore.

I'm no longer an instrument of national policy.

Lemme know if you make it to the Tri-Cities area (Bay, Saginaw, Midland
area) Ed.


--
Ryan, KC8PMX
FF1-FF2-MFR-(pending NREMT-B!)
--. --- -.. ... .- -. --. . .-.. ... .- .-. . ..-. .. .-. . ..-.
... --. .... - . .-. ...
"W1RFI" wrote in message
...
The Emmaus test site video (test area #3) should be pretty representative
of the "main.net" system ... test area #4 is the Amperion OFDM system.
There could be others that might have different "signatures" ...

Just as a mnor correction, test area #4, in Briarcliff Manor, NY, is an
Ambient
system. The Amperion system is also OFDM and has a very similar sound. I
found
it easily in Whitehall, PA, once I drove into the test area.

73,
Ed Hare, W1RFI

Dave Shrader wrote in message .net...
The ARRL site, http://www.arrl.org/tis/info/HTML/plc/#Field , provides
links to the following information:

"PLC is a "carrier-current" system, designed to intentionally conduct
signals using electrical wiring. Although a carrier-current device is an
unintentional emitter, because the power lines have such a significant
potential to radiate and because a practical carrier-current device
generally needs more signal than the permitted conducted emissions
levels for unintentional emitters, carrier-current devices are not
required to meet those conducted-emissions limits, but are required to
meet the general radiated emissions limits in Sec. 15.209.

§ 15.209 states that the radiated emission limits of intentional
radiators generally can't exceed the field strength levels specified in
the following table:

Frequency (MHz) Field Strength (microvolts/meter @meters)

0.009-0.490 2400/F(kHz) 300

0.490-1.705 24000/F(kHz) 30

1.705-30.0 30 30

30-88 100 3

88-216 150 3

216-960 200 3

Above 960 500 3

Carrier-current devices are "Verified" as described in the Part-15
rules. This means that the manufacturer is required to test them to
ensure that they comply with the FCC regulations. Under the present
rules, they must be tested at 3 typical locations. "

What's the FCC definition of "typical locations"??

Note that the HF Spectrum allows a S8 to S9 signal level, 30 uV/m at 30
meters distance.

15.209 is the problem, it's grossly outdated, did not foresee anything
like BPL and the limits needs to be revised downward which is one
piece of this brawl. Ref: Tailpipe emissions regs, same basic problem,
different pollution media.

Another piece of it is that the BPL crowd wants permission to bust the
already inadequate limits in 15.209. They're playing the regulatory
loopholes game. The Japanese jumped past their regulatory Catch-22
techo-babble and abolished BPL period. We need to follow the Japanese
lead and we're working on it.

w3rv

Look at that BPL antenna in the foreground!!!!

Roger Halstead wrote:

On Wed, 15 Oct 2003 20:20:31 GMT, "Jim Hampton"
wrote:


Brian,

I don't know about you, but I received a whole week pass from Belleveu

I'm not sure about the crazy part, but...
For those who have a "good" broadband connection here is a panoramic
view from the top of my tower. If you don't have broad band, don't
waste your time. This thing is 19.5 megs. It should take under a
minute with cable, and close to 10 minutes with ADSL, so you can
imagine how long it'd take with a dial up connection.
http://www.rogerhalstead.com/towerview.htm
I stood on the triangular top plate of the ROHN 45 G (at 100 feet) and
shot the entire series hand held. The camera was set to manual, but
the wind was gusting to 20 MPH plus, so a few of them didn't line up
good enough for a proper match when making the panorama.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)

What happens to a BPL signal when a 100 or 500 watt mobile is under the
line?

The 10 house area may be a good place to hold a mobile antenna shoot out.

If you can't hear anything, send in complaints about the noise. If the home
owners can't see anything on their computers, I am sure they will complain.

Normally power line noise we hear is power wasted to ground from arcing and
that costs the power companies money because it is not metered power and
therefore not billable. Report areas where there is high noise. You will
be surprised--sometimes it goes away totally!
--
Rudy Marcelletti, K8SWD
"Dick Carroll" wrote in message
...
W1RFI wrote:
Exactly, must sent in complaints. Or the 'utilities' will say...."we
got
very few complaints"


Some of the trial areas have about 10 homes in them. The industry still
says,
with a straight face, we had no reports of interference, so this
"proves" we
won't interfere.

73,
Ed Hare, W1RFI




Something occurred to me - If the BPL test areas are using only
2-22 mHz, they they WILL avoid critical interference complaints
from Low Band VHF Public Safety users and others, and will be able to
say "We had no complaints from (same)", while conveniently overlooking
the fact that they couldn't have had complaints because they didn't
generate any interference to those operations!

(I mentioned this to contacts in PubSafety. I also suggested spectrum
analysis to determine what spectrum is actually being used.)

So we are very careful to make certain that the interference we
find actually is BPL. And since they are only using a portion of the
spectrum that would be used under full implementation of BPL, they
will be able to say, about users of spectrum which they aren't testing
within, "We got no complaints from them" when in fact the interference
will occurr only when BPL is fully implemented!
And of course there will be no such complaints inasmuch as no
interference was generated! So those users get blindsided, having
assumed there would be no interference from BPL.
It's amazing how well they're playing both ends against the middle.
One REALLY has to think about all this to stay on top of this mess.

The longer one looks at BPL as presented the worse it smells.

Dick