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