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  #31   Report Post  
Old October 13th 03, 09:19 PM
Carl R. Stevenson
 
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"Dick Carroll" wrote in message
...
Dave VanHorn wrote:
After having gone to the ARRL site and listened to the examples, all I
can say is it sounds just like precipitation static and/or loose
connections. No way would I be able to identify one from the other.
I'm just going to have to complain every time I hear noise and make
recordings. If it's noisy enough to be a problem it should be fixed.



Any hope of us non-arrl members getting something to listen to?




Surely that file isn't on the members-only side of the site, is it?

Certainly it shouldn't be, and if so I intend to protest.


It isn't Dick ... it's open to the world.

Carl - wk3c


  #32   Report Post  
Old October 13th 03, 09:31 PM
Dave VanHorn
 
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Surely that file isn't on the members-only side of the site, is it?

Certainly it shouldn't be, and if so I intend to protest.


It isn't Dick ... it's open to the world.

Carl - wk3c



Apparently my "nevermind" is taking a while to propagate


  #33   Report Post  
Old October 14th 03, 01:51 AM
Brian Kelly
 
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Dick Carroll wrote in message ...

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!'??



BPL has a unique "signature" (in the spectral/time domains) that can be
used to ID it.

Since there are different systems (SS from main.net and OFDM from Amperion,
for example) they have different signatures, which are distinct from other
sources
of interference and more traditional power line noise (of course the
utilities are
responsible for fixing the latter, too ... though their record is poor).



So to repeat, how does the average ham, whom you have exhorted to
"make sure it's BPL that you're complaining about", go about detecting
and sorting which is what, given that spectral analysis gear, and the
training to use it if it was available, is virtually nonexistnt in the
average hamshack? Is there a aural signature or more than one for the
different BPL modes? Is the Emmaus test site video/audio clip
reresentative enough to make the call, or is something more needed?


There's no mistaking the BPL signals in the Emmaus test area which are
SS although there's some discussion on that point. I didn't know what
to look for on my first pass through Emmaus and found all sorts of
crud particularly in the extensive commercial area. But I found a very
odd-sounding strong clicking noise in the area around the Emmaus High
School and reported it to Carl and Ed Hare who then told me the stuff
sounds like geiger-counter clicks. So I'd nailed it out of the chute
with just my little TS-50 HF mobile xcvr and a 2M magmaount whip. I've
probably heard every form of QRN/QRM out there by now and there is
*no* mistaking the BPL in use in Emmaus. The stuff grabs yer AGC and
it's all over.

The ARRL audio tracks and files don't do it justice, the spikes it
kicks out are too sharp and short to be captured properly with the
consumer-level digital recording/playback equipment used to generate
the recordings. OFDM is another form of the beast which I haven't
personally tuned on-site yet but the ARRL recordings ought to give you
the drift.


I expect that if it was indeed BPL RFI it would follow the power grid
pretty closely with signal strength highest when close, and tapering off
with distance away from the lines. But from the one report posted here
of a ham who said he heard it from a distance of 60 miles, seems like
propagation will play into the picture-to be expected at HF as all
experienced HF ham operators know. Or maybe *he* mis-identified it!

So who do hams call for assistance, the ARRL? I haven't seen anything
from them suggesting that.


Unfortunately the only help available is via the FCC and the ARRL is
beating the FCC into the ground over this one.

I seriously doubt the economics of BPL will ever bring it where I
live, even if it is approved, but others need to know.


w3rv
  #34   Report Post  
Old October 14th 03, 02:55 AM
Jim Kelley
 
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"Carl R. Stevenson" wrote:

"Dave VanHorn" wrote in message
...

After having gone to the ARRL site and listened to the examples, all I
can say is it sounds just like precipitation static and/or loose
connections. No way would I be able to identify one from the other.
I'm just going to have to complain every time I hear noise and make
recordings. If it's noisy enough to be a problem it should be fixed.


Any hope of us non-arrl members getting something to listen to?


Dave,

The ARRL video is not in the "members only" part of the site ...
it's easy to find from the articles on BPL in the public area.

Carl - wk3c


http://216.167.96.120/BPL_Trial-web.mpg
http://216.167.96.120/BPL_Trial-small.mpg
  #35   Report Post  
Old October 14th 03, 05:28 AM
Ryan, KC8PMX
 
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Saw Roger K8RI's post as well, but will try to answer as well.

Bay County has around 300 hams listed, Saginaw has almost 500 listed, and
Midland has about 230-250 listed as hams living in those areas. The Midland
Amateur Radio Club has about 80 members with about 20-30 actually active.
The Bay Area Amateur Radio Club has about 35-50 club members and has about
20 or so that are active and the Saginaw Valley Amateur Radio Association
has about 30 members with somewhere between 15-20 members active.

It's kinda funny though, with almost a thousand hams between 3 counties, I
sure as hell do not hear much on the ham bands, both HF and VHF/UHF. One
would think that they would hear a ton of radio usage but thats not the
case.... I would say that maybe 10-20% of the total population around here
is actually active on a regular basis. (that's probably true about alot of
things though...


--
Ryan, KC8PMX
FF1-FF2-MFR-(pending NREMT-B!)
--. --- -.. ... .- -. --. . .-.. ... .- .-. . ..-. .. .-. . ..-.
... --. .... - . .-. ...

"Howard" wrote in message
...
On Fri, 10 Oct 2003 22:20:31 -0400, "Ryan, KC8PMX"
wrote:

Just found out today listening to a local, reputable radio station that

Bay,
Saginaw and Midland Counties in Michigan are going to be "test sites" for
BPL, at least for Michigan. I don't know when it will be an actual

reality,
as opposed to being in the planning stages, but will keep current with

their
project!


Ryan KC8PMX
Midland, Michigan

What the "ham density" like in the Tri-Cities these days? Moved away
27 years ago (Bay City/Essexville) and not having been a ham then I
was out of touch with such things. I do know that it wasn't too high
a population density overall - perhaps they are targeting low ham
population areas in the testing so they can show a low interference
complaint volume?

I think Carl's on track in his post; the more credible the reports of
interference the more likely they will be taken seriously.

Howard





  #36   Report Post  
Old October 14th 03, 12:54 PM
W1RFI
 
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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

  #37   Report Post  
Old October 14th 03, 12:58 PM
W1RFI
 
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Yes and no Carl.... if it makes it impossible to RECIEVE our local broadcast
stations, I would think that the local broadcasters would be VERY interested
to know that nobody is getting thier signal, except cable subscribers.


A number of hams have reported to the FCC that there was interference to the AM
BC band in Emmaus, PA. In my last visit there, I tuned the AM band while
parked in the trial area and heard no BPL interference whatsoever. From the
looks of the comments, someone posted a "template" and urged hams to file it.

The BPL problem appears to be primarily one of HF and low VHF. There may be
some harmonics into the TV channels, but those harmonics will be a LOT weaker
than ours are, so we need to be careful of what we wish for.

73,
Ed Hare, W1RFI
  #38   Report Post  
Old October 14th 03, 01:04 PM
W1RFI
 
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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.

73,
Ed Hare, W1RFI

  #39   Report Post  
Old October 14th 03, 01:09 PM
W1RFI
 
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So to repeat, how does the average ham, whom you have exhorted to
"make sure it's BPL that you're complaining about", go about detecting
and sorting which is what, given that spectral analysis gear, and the
training to use it if it was available, is virtually nonexistnt in the
average hamshack? Is there a aural signature or more than one for the
different BPL modes? Is the Emmaus test site video/audio clip
reresentative enough to make the call, or is something more needed?


Carl had suggested that those that suspect they have BPL interference contact
me. ARRL can help ask the right questions and analyze the pattern. Many hams
do have the abiltity to use an oscilloscope and may be able to do some
time-domain analysis themselves.

I expect that if it was indeed BPL RFI it would follow the power grid
pretty closely with signal strength highest when close, and tapering off
with distance away from the lines. But from the one report posted here
of a ham who said he heard it from a distance of 60 miles, seems like
propagation will play into the picture-to be expected at HF as all
experienced HF ham operators know. Or maybe *he* mis-identified it!


That is almost certain. At a few hundred homes and BPL power levels, it is not
possible for a small number of signals to propagate by skywave at a level
strong enough to be heard. When there are tens of thousands of simultaneous
signals, that may be *just* possible, but not at all certain.

So who do hams call for assistance, the ARRL? I haven't seen anything
from them suggesting that.


I have just completed the draft of the letter that ARRL will send to hams in
the trial cities, asking for reports and offering to help vet them before they
are sent. It should go out this week.

73,
Ed Hare, W1RFI
ARRL Lab

  #40   Report Post  
Old October 14th 03, 01:10 PM
W1RFI
 
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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



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