Pete,
From your point of view, the first step is to make sure
your transmitter is 'clean'. From your neighbor's point
of view the first step is to complain to the person causing
the interference, if possible. Sounds like both of you have
done that. The second step is to complain to the service
provider (cable, telephone, power, etc.), it's their
responcibility
to provide 'clean' service to the user. (That responcibility
only
extends as far as the service entrance in most cases. From
there
to the modem, TV, whatever, is usually the user's
responcibility.)
RFI isn't ~that~ unusual so the provider should know what to do
about it. If you have 'problems' with the provider, if the
provider
isn't reasonable at all, then the next step is to complain to
your state's utilities commission. It's their responcibility to
make sure the provider is doing what they are supposed to do.
In the mean time, or in addition to what the provider does,
your neighbor can install RFI devices on ~his~ portion of the
cable/power line/whatever. The 'trick' is in knowing where
'their'
portion ends and 'his' portion begins. (I'm sure the provider
will
let him know where that point is! LOL)
It 'sounds' worse than it really is, but doing things
'properly'
is one of the 'keys'. A bunch of us have 'been there, done
that'
so you're not alone. Good luck...
'Doc