Dwight Stewart wrote in message ...
From the July 2003 issue (pg. 37) of PC World Magazine...

A brazen new competitor to DSL and cable is
"within striking distance of being the third
major broadband pipe into the home," says FCC
Chairman Michael Powell. Broadband of power
line, or BPL (currently being offered in pilot
programs by a dozen or so utilities around the
country), promises to deliver high-speed
Internet access straight from the electrical
socket in your wall. Long written off as an
also-ran technology, BPL has new spark, thanks
to technical advances that address problems of
interference and in-line transformers that
scramble signals. The last hurdle will be getting
FCC approval. Considering Powell's enthusiasm -
the general belief that BPL will cost less than
cable and DSL - a green light could be imminent.

While everyone would obviously like cheaper broadband internet access, my
principle concern is the possible interference with ham radio out here in
the real world - the real world of corroded and rotted old power lines,
decades old transformers and power stations, and the ancient (often poorly
grounded) electrical wiring in old homes and buildings throughout this
country. Like many others, I suspect this technology is going to have a
dramatic impact on ham radio.

It sure will, if it's allowed to be implemented.

FCC Docket 03-104 addresses implementation of these systems. Comments
close today. ARRL submitted a 120 page paper on the effects of the
proposed systems. None of it is good news for hams.

Does anyone know about these touted "advances that address problems of
interference" mentioned above? Are these "advances" really going to prevent
potential interference problems out here in the real world?

Basically they come down to two ideas:

1) spectrum masking, which consists of not allowing the BPL systems to
use frequencies in the ham bands. Which is fine until something
nonlinear in the system causes intermodulation products, harmonics or
other spurious signals to fall in the ham bands. This method was used
to stop HomePlug and other in-building systems from tearing up 80
meters - AFTER our own W1RFI and other ARRL folks got the manufacturer
to recognize the problem.

2) "improved modes and modulations", which permit the use of lower
signal levels and hence lower signal leakage. Supposedly.

The BIG problem is obvious to anyone who actually goes out and looks
at a typical aerial distribution system. Lots of nice, long wires, way
up in the air, running all over everyone's neighborhood. Put a little
RF in them and watch it radiate.

Heck, one of the biggest problems in access BPL is that the lines are
"lossy" at RF. They're "lossy" because they radiate!

You can read the comments of others and leave your own at the FCC
website, via the ECFS system. Check out what the ARRL is saying and
doing at the ARRL website.

73 de Jim, N2EY