Sorry Ed ... I miss-spoke ... they both begin with "A" and I
got the backwards ...

Carl - wk3c

"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

Dick,

I'm not at all sure who uses what spectrum in the areas where they are
testing BPL, but I'd bet coffee for a week that those folks studied the
situation carefully before proceeding. Where did they test (I don't know of
all areas and I'm asking a sincere question)? The "promise" of BPL is to
serve areas that are not served well by cable or DSL. Did they test a
fairly substantial area in the country where they could demonstrate
far-flung connections to the BPL, or did they test in densely populated
areas that are already served by various broadband connection (where fire,
police, emergency, etc. are very likely not on low band VHF)? Also, FM
broadcasting is usually located near large population areas (since signals
tend to die off pretty quickly after 40 or 60 miles). This means that if
you have BPL in a city, it is unlikely that residents will experience
capture effect on the FM receivers since they will be getting *huge* signals
on their FM receivers. I note the "neon sign" comment in the thread. Neon
signs are usually found in cities. Those test sites are likely located
either in a city or in an area where the money interests already checked the
FCC site to ensure no low band VHF use by police, fire, ambulance, etc.

Any thoughts on this, or am I crazy?


73 from Rochester, NY
Jim AA2QA


"Dick Carroll" wrote in message
...

Before I retired I was a field engineer working with a statewide
public safety organization which uses low band VHF for base to car
communications statewide, and that system is still virtually as I left
it nearly 10 years ago. I have learned that they are aware of the BPL
docket and filed in opposition, and have some idea that it will impact
their communications, but I wonder if they have a clear view of what
looms should BPL be widely implemented. While working I spent
considerable time on RF noise issues, and I am rather sure that such a
radio system cannot coexist with BPL.

What happens is that when the noise intererence reaches a certain
level, in a FM receiver the limiter saturates, and even a strong
on-channel signal will not cause the squelch to open. The reciever
remains quiet, and the call is unanswered.
I was able to locate one troublesome noise source which was reported
as repeater trouble in that the repeater would ocassionally go quiet in
mid-transmission when a car was calling in. By the time I would drive
the substantial distance to the repeater, a thorough checkout found no
problem with the repeate equipment whatever. After several fruitless
trips and attempts to find the trouble, I finally happened to be onsite
when the trouble appeared, and it was all limiter saturation. Looking
around outside while the noise was present in an attempt to spot a
source in the local rural area, I soon found it- an arc welder in a shop
several hundred yards away. When the welder was in use, the arc caused
noise that saturated the receiver limiter, effectively shutting down the
repeater. We relocated that repeater to a more isolated site where it
still functions as intended.
That example is but one case. BPL will, following power lines, also
follow roads and streets since power lines follow streets and
highway/road rights of way everywhere - the same places where police and
highway patrol units'communications are active. The interference issue
simply WILL cause something drastic to be implemented, what I don't
know. If common sense has anything to do with it, BPL will be sent
packing. Widesp[read implementation of BPL spells the end of lowband VHF
use by public safety organizations. And with states' budgets in the
deflated condition they are in most places, the funding will not be
available to replace those systems in the forseeable future.

I just called a former co-worker who is still working, and asked him
if the organization knows that there is a BPL test site in the state.
He said they did not. I suggested he might want to pass the word on up
the chain so that they might want to send a mobile unit into the test
area to get firsthand information on just what the effects might be. I'm
also passing along all the info I've gathred here and from other
sources. We'll need all the help we can get on this turkey.

In short, I'm coninced that while APCO and others may know
of the BPL docket I wonder if they have a very clear concept of
what it will do to them where low band VHF is used.
For instance, what have you heard from the state of Calorfinia, which
is reported to use low band VHF for their statewide Highway Patrol, and
has over 5,000 mobile units with no telling how many base stations?
I have heard nothing whatever from anyone there on BPL.

It seems evident that the BPL people are not publishing the existance
of these very small test sites any more widely than necessary. So, they
won't garner very many,if any, BPL-specific complaints, will they? And
they'll be able to say "We must not be causing destructive interference
since we haven't generated complaints". Of course limiting the numbers
of users in test areas to a very few drastically limits the amount of
interference potential. With so few BPL users online there *won't* be
much interference caused, thus few or no complaints. Then they will
conveniently pass over this fact, and the decision makers won't know the
difference.

Someone with clout needs to take them to task with the FCC and force
them to use much broader test areas with much more realistic noise
levels generated so that a more realistic noise picture can be
evaluated. As it stands, they may well get what they want by default.

Dick W0EX



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.525 / Virus Database: 322 - Release Date: 10/9/03

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 -

Dick you bring up good technical and adminsitrative examples. My
career too is in land mobile (public safety and railroads) and while
there is plenty of trunking and digital taking place above 450 Mhz,
there is also plenty of low and high band activity, and always will
be.

The ARRL seems to be doing a good job studying the BPL issue and
informing the ham community, but the public safety, industrial,
business, government, etc., users will have a louder and more credible
voice (safety of lives & property, commerce, homeland security, etc.).

I am wondering what the ARRL is doing to form coalitions with other
(non-amateur) stakeholders, and to build concensus that has a loud and
effective enough voice with the Commission and with Congress.
Politically and techincally, the ARRL and/or the amateur community
cannot stop this on their own.

73
Dan (K0DAN)


On 14 Oct 2003 20:42:09 GMT, Dick Carroll
wrote:

dt wrote:
Hams are not the only users of the affected spectrum. They may be the
most vocal, but perhaps the easiest to discredit or deflect.

What about the other users of the HF-thru-VHF spectrum? Police, Fire,
EMS, Federal Government, Business, Utilities (the power companies
themselves), Military, Aviation, etc., etc.?

Do they not have consultants who are in touch with industry affairs?

Does APCO (and other industry communications associations) not have
knowledge about BPL and a position on it?


Before I retired I was a field engineer working with a statewide
public safety organization which uses low band VHF for base to car
communications statewide, and that system is still virtually as I left
it nearly 10 years ago. I have learned that they are aware of the BPL
docket and filed in opposition, and have some idea that it will impact
their communications, but I wonder if they have a clear view of what
looms should BPL be widely implemented. While working I spent
considerable time on RF noise issues, and I am rather sure that such a
radio system cannot coexist with BPL.

What happens is that when the noise intererence reaches a certain
level, in a FM receiver the limiter saturates, and even a strong
on-channel signal will not cause the squelch to open. The reciever
remains quiet, and the call is unanswered.
I was able to locate one troublesome noise source which was reported
as repeater trouble in that the repeater would ocassionally go quiet in
mid-transmission when a car was calling in. By the time I would drive
the substantial distance to the repeater, a thorough checkout found no
problem with the repeate equipment whatever. After several fruitless
trips and attempts to find the trouble, I finally happened to be onsite
when the trouble appeared, and it was all limiter saturation. Looking
around outside while the noise was present in an attempt to spot a
source in the local rural area, I soon found it- an arc welder in a shop
several hundred yards away. When the welder was in use, the arc caused
noise that saturated the receiver limiter, effectively shutting down the
repeater. We relocated that repeater to a more isolated site where it
still functions as intended.
That example is but one case. BPL will, following power lines, also
follow roads and streets since power lines follow streets and
highway/road rights of way everywhere - the same places where police and
highway patrol units'communications are active. The interference issue
simply WILL cause something drastic to be implemented, what I don't
know. If common sense has anything to do with it, BPL will be sent
packing. Widesp[read implementation of BPL spells the end of lowband VHF
use by public safety organizations. And with states' budgets in the
deflated condition they are in most places, the funding will not be
available to replace those systems in the forseeable future.

I just called a former co-worker who is still working, and asked him
if the organization knows that there is a BPL test site in the state.
He said they did not. I suggested he might want to pass the word on up
the chain so that they might want to send a mobile unit into the test
area to get firsthand information on just what the effects might be. I'm
also passing along all the info I've gathred here and from other
sources. We'll need all the help we can get on this turkey.

In short, I'm coninced that while APCO and others may know
of the BPL docket I wonder if they have a very clear concept of
what it will do to them where low band VHF is used.
For instance, what have you heard from the state of Calorfinia, which
is reported to use low band VHF for their statewide Highway Patrol, and
has over 5,000 mobile units with no telling how many base stations?
I have heard nothing whatever from anyone there on BPL.

It seems evident that the BPL people are not publishing the existance
of these very small test sites any more widely than necessary. So, they
won't garner very many,if any, BPL-specific complaints, will they? And
they'll be able to say "We must not be causing destructive interference
since we haven't generated complaints". Of course limiting the numbers
of users in test areas to a very few drastically limits the amount of
interference potential. With so few BPL users online there *won't* be
much interference caused, thus few or no complaints. Then they will
conveniently pass over this fact, and the decision makers won't know the
difference.

Someone with clout needs to take them to task with the FCC and force
them to use much broader test areas with much more realistic noise
levels generated so that a more realistic noise picture can be
evaluated. As it stands, they may well get what they want by default.

Dick W0EX




What is the ARRL doing to join forces with other affected spectrum
users, perhaps forming a task force to promote common interests?
Lobbying senators and congressmen, the Commission, NTIA, etc.?

If the utilities' strategy is to divide and conquer, it appears they
are being very effective.

73
Dan (K0DAN)



On 14 Oct 2003 14:03:08 GMT, Dick Carroll
wrote:


W1RFI wrote:


You raise an interesting question, Carl. How exactly should the
average ham go about proving that the RFI is indeed BPL, when the BPL
people say
"That's not us!'??


In the case in Emmaus, the PPL rep told a reporter that Carl had misidentified
a "neon sign" (in a residential neighborhood) as BPL. First, Carl is
professionally adept with spread spectrum, so he knows what an SS signal sounds
like. The signal was heard only in the trial area and when I was in Emmaus, I
worked with a local in the trial area who downloaded files for me. When the
download started, the noise started; when it stopped, the noise stopped.

What really proves it to be not a neon sign, however, is that the time-domain
(oscilloscope) signature of the received signal does not have a pronounced
120-Hz signature. Had the PPL representative actually looked at the signal, he
would have known that his "explanation" was pretty transparent.

I have extended by email a very cordial inviation for the PPL folks to attend a
local club talk I gave; they did not respond. I then emailed a cordial
invitation to work with them on interference issues; they did not respond. This
boggles the mind, because if I were about to invest millions of dollars of my
company's money and a national organization came to me and told me that there
was a serious problem with the technology, and offered to drive over 200 miles
just to show it to me, I think I would spend the hour or two and take a look.



It's beyond obvious that the BPL people are adamantly intent on
stonewealling and bypassing ham radio and anything else that tries to
get in the way.
They're aware that many of the impacted spectrum users are so widely
scattered that much of the interference caused by BPL even when it
becomes widely implemented they won't be noticed due to their limited
exposure caused by lack of adequately close proximity.

Hams, which *are* pretty well scattered throughout the population,
should be ignored and their complaints deflected by such incorrect
assertions as the above "neon sign" explanation. Make it so that there
is so much question as to hams' competance to make such a call they can
be portrayed to be wrong, whatever the facts. It's obvious obfuscation
and an end-run around us, and whatever other protesters weigh in that
can be similarily deflected. They hope that the "serious" users of that
part of the spectrum will prove to be so few and widely scattered that
their protests will be few and managable.

And once BPL installations are widespread, they know it would demand
a clearly demonstrated, very serious interference problem to csuse its
abandonment, and they don't think that will happen. They maybe right.
If so many users sign on that the sheer numbers of BPL users overwhelm
all the protests of spectrum pollution and damage to communications
sheer numbers and politics will prevail in their favor, they believe.
All they really need to do is get it approved and "out there" in large
amounts in most populated areas, then the situation will take care of
itself, they think.

If allowed to proceed, BPL will forever change usability of the HF and
Low VHF part of the spectrum.

On Tue, 14 Oct 2003 19:26:53 -0500, "Clint" rattlehead at computron
dot net wrote:

Write or call your local AM broadcast stations and tell them that
thier signal is being wiped out and you can't recieve them.

Only if it's true... Don't cry wolf, or we won't be believed when we
need it.

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

Clint
KB5ZHT

Proximity to the power grid would be the main clincher, IMO, but what
about skywave propagation? That stuff could go around the world at QRP
levels!

No single signal will be heard by skywave; the power levels are too low.

Here's the math:

Power level: -50 dBm/Hz
Corrected to 3000 Hz: add 35 dB
Coupler loss: -10 dB
Powerline antenna gain: -10 dB
Path loss VOACAP: -110 dB

That gives a received signal level of -145 dBm/3 kHz, well below the ambient
noise at any HF station.

And millions of them may not make as much difference as we might think. They
way these systems work, they share bandwidth between many users, so the signals
are time muliplexed, so only one signal on a particular power line is active at
a time. 100 shared signals have the same peak field strength as 1 signal, for
the most part. So there may be 10,000 simultaneous emitters in a metro area.
That will add 40 dB, bringing it just above the band noise -- interesting, but
not conclusive.

The problem is local, and our concerns should be focused there.

73,
Ed Hare, W1RFI

Ed, is there a URL where we can view the location of all the test sites
now in use? How about future planned test sites?

Email me privately. I have put one together, but it has a lot of Mapquest maps
that are copyrighted, so I am not posting it. It is essentially for the "fair
use" of HQ staff and those working on the BPL issues in the field.

73,
Ed Hare, W1RFI

Ed, is there some reason why radio amateurs cannot document their
complaints,
if they exist, to the FCC directly?

They can, if they are certain that they are documenting BPL and not another
source. It is possible to misidentify other sources as BPL, so having a
time-domain and frequency-domain analysis of the received signal will be an
important cross check.

73,
Ed Hare, W1RFI

Well.. I've been rather turned off by the "luddite"s in my local area.
Until recently, our league section person was the head of the VEC group
locally, an she refused to allow farnsworth testing for CW.

That is pretty serious. I have cc'ed Bart Jahnke, ARRL's VEC Manager, who will
contact you for more details. Farnsworth testing is the "standard" for amateur
exams and refusing to give it would be a pretty serious breach of ethics.
Thanks for reporting it.

I do see that the ARRL is going to be very important on this issue, and I'm
available to make observations within any reasonable driving distance of my
QTH. (Muncie Indiana)

Wether I'm a member or not shouldn't affect the validity of my data.

You are correct, but your being a member or not will affect how much ARRL is
able to do in what you have deemed to be an important area. The important
things it has done so far have been paid for by someone else -- at 12 cents a
day.

I am interested to know how you're calibrating your mobile to get uV/Meter
measurements.

I did a rough calibration of my mobile-whip dipole by comparing it against a
half-wave dipole at the same height. From there, is is easy to calculate field
strength.

I have a draft document on the measurement method -- email me at
and I will send it along to you. Feedback welcome.

73,
Ed Hare, W1RFI

At this point, they are probably still actively persuing investors.
If the investors get the idea that there's a potential dead end here, they
will go elsewhere.
The ones that are already in though, will be mad at us, most likely.

The investors may have already gotten some of the idea:

http://moneycentral.msn.com/scripts/...qd&Symbol=ABTG

The discussion board at:

http://ragingbull.lycos.com/mboard/b...ABTG&read=2259

is interesting, although only a little bit of discussion on what they term
"hammies." Interestingly, they seem blissfully unaware of the growing concern
and discussion about the interference potential to all of HF. I would imagine
that the BBC report alone should have sent the stock even lower, and when the
NTIA study is done, if what I found in Emmaus, PA is reported as found, things
may not look real good for the industry. I believe that it is easy enough to
sign up to be able to post to the board, although I think it best that I not do
so.

To my knowlege, Ambient (ABTG) is the only publically traded stock, although
Main.net may be traded in Israel.

73,
Ed Hare, W1RFI