At 05:53 PM 9/26/2003, W0CP wrote:

Most of the discussion so far has centered on the adverse effects of BPL on nearby hams. Is there also a possibility that this system would appropriate the HF spectrum worldwide?

Put another way, what is the potential for BPL signals to propagate via ionospheric skip?

Here's Ed Hare's response to a similar question from me: -- Tom

Subject: RE: propagation? Date: Wed, 20 Aug 2003 19:19:42 -0400 From: "Hare,Ed, W1RFI" <w1rfi@arrl.org> To: "Frenaye, Tom (Dir, NE)" <frenaye@pcnet.com> Cc: "Imlay, Chris" <w3kd@arrl.org>

Depends what math you use. :-) At the FCC limits, 10,000 devices in Baltimore would be just about at the noise floor of a typical residential environment in Atlanta. To a real quiet location, W8JI?, they would probably be about +10 dB.

But if, as I suspect, these things are really about 20 dB over the FCC limit skyward, then this ratchets up quite a bit. And of you get 100,000 devices 20 dB over the limits, it will start to get ugly fast.

I am waiting, however, for the NTIA data on actual measurements. I think I have them flagged to look at greater heights than the lines, possibly with some terraine help. If we get data from then, I can then run the total power level through some VOACAP and maybe have another nail for the coffin. I would rather use NTIA data than anything I might develop because it will be less suspect by the FCC and harder for the industry to refute.

73, Ed Hare, W1RFI ARRL Lab 225 Main St Newington, CT 06111 Tel: 860-594-0318 Internet: w1rfi@arrl.org Web: http://www.arrl.org/tis

...

-----Original Message----- From: Frenaye, Tom (Dir, NE) Sent: Wednesday, August 20, 2003 2:49 PM To: Hare,Ed, W1RFI Cc: Imlay, Chris Subject: propagation?

If BPL is deployed at the levels requested, will people outside of the US be able to hear it? The aggregate of all of those noise sources certainly ought to be loud enough?

-- Tom

===== e-mail: k1ki@arrl.org ARRL New England Division Director http://www.arrl.org/ Tom Frenaye, K1KI, P O Box J, West Suffield CT 06093 Phone: 860-668-5444