In article , "Carl R. Stevenson"
writes:

The fact of the matter is that the ONLY serious technical studies
presented to the FCC in their Notice of Inquiry on BPL came from
the good work of Ed Hare, W1RFI, and his colleagues at ARRL.

Yep.

The "access BPL" industry has done essentially nothing but "hand-
waving" and ignoring/denying that the problem exists. They want
to make $$$ ... and they don't appear to give a damn about the
impact on the other users of HF.

Besides ignoring the technical weaksnesses of BPL, they're also ignoring the
really poor business model that drives it.

That they claim that "power wires don't radiate" (when NEC models,
as well as plain old common sense, indicate that they do) and that
"BPL is a 'point source' radiator" (how one can make that argument
when what they are building is essentially a large, distributed antenna
system) clearly indicate their deep state of "don't confuse the issue
with the facts" denial.

It should also be mentioned that the location and existence of test sites was
kept very quiet until ARRL/W1RFI blew the whistle. Representatives of radio
services were neither invited nor even informed of BPL tests.

One of the simplest and most positive tests is to turn the BPL service on and
off and observe changes in interference, thus identifying if BPL is the source.
But to my knowledge no BPL test site has done such tests.

The "promise" of BPL is to serve areas that are not served well
by cable or DSL.

While DSL is not available in all areas due to the distance from the
central office factor and the phone companies' slow rollout in areas
of lower population density, acccording to the latest statistics I've
seen, cable "passes" 97%+ of US households. There are also
internet via satellite services available, using dishes like (sometimes
the same dish as) satellite TV services. There are also "WISPs"
who provide services using more appropriate spectrum in the low
microwave bands.

Agreed. But there's mo

Access-BPL is really meant as a "last mile" system, to avoid the need to wire
houses for cable or install special filters and modems. So the fiber still
needs to get within a certain distance of your house, same as with DSL.

The main selling point for Access-BPL is that you can just plug a BPL modem
line into any wall outlet, and you're connected. Your entire house wiring
becomes an internet connection - and also an antenna to radiate BPL noise. So
even if all services are buried, you'll still have noise from the house wiring
radiating.

The BPL signal travels on the medium voltage (4-13 kV) distribution wire(s) and
is then coupled around the pole pig transformers with special couplers. In most
neighborhoods other than those of very low density, a transformer feeds a few
homes, so everyone's wiring gets the BPL signal even if only one customer is
signed up. Indeed, if a coupler is left in place, everyone's house wiring gets
the signal even if no one is signed up.

The couplers and fiber/MV converters mean that BPL has significant installation
costs even if they don't have to do any installation in customer's houses.

The business model for BPL is WAY less than compelling and its
technical suitability is poor as well, not only because of interference
TO the wide variety of licensed HF users, but also because of the
potential for interference to the BPL system FROM those licensed
users ... and BPL will have NO claim of protection from such interference.
My belief is that consumers deserve a more robust and reliable means
of receiving broadband internet services - one that doesn't present the
(bi-directional) interference issues of BPL - and that there are a number
of such alternatives available already.

Very well-said and absolutely true.

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)?

Ed has a better overall view of the current deployments of BPL, but I know
they are few and limited in scope at the moment.

There are also different systems being tried out, so what you hear on the
Emmaus test site video may not be the same as what is experienced elsewhere.

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.

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.

What about harmonics? The BPL signals on the video sounded like they had pretty
fast risetimes.

I note the "neon sign" comment in the thread. Neon
signs are usually found in cities.

The "neon sign" assertion by the representative of PPL (the Emmaus
BPL system operator) is *pure* BS ... the signature was SS, NOT
a neon sign ...

And did they turn off the BPL for a few moments to demonstrate that it was a
neon sign and not the BPL? One guess.....

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.

I think you're giving them FAR too much credit for caring about anything
but deploying BPL ...

Exactly!

Something else to watch out for.....

Because different systems are being tried in different locations, proponents of
each system will probably proclaim the *their* system doesn't have that problem
- what you heard at the Podunk site is Brand X BPL.

73 es tnx Carl de Jim, N2EY