Topband: Power line communication (PLC) - Trends in Holland

[k3ky@erols.com]

I fear that Ulli has it pretty much right. Sounds like PLC will be a
disaster in city environments, and possibly even in some suburbs.
Perhaps the HF SWL's of the world have essentially no political
clout, whereas the hams are seen as still having a little influence.
I bet that firmware changes in these infernal digital noise boxes
could re-enable the 8 or so channels that will be notched at first, so
that all of the 80+ channels are enabled. Once you have a large
installed base of these devices, it would be impossible to shut
them down. The only option would be a major upgrade such as
fiber-to-premises (and fiber network interconnects on site),
which still seem to be a long way off. This will
obviously be a major disaster for SWLs. They are politically
insignificant, however, and will be crushed under the tidal wave
of the (home) computer revolution and the growth of the internet.
Retiring to a rural location may become the only remedy for those
living in cities. 
Just how far a given 'nest' of interference such as a 10-story
building will radiate remains to be seen. Certainly such emitters
will contribute to the rise of the overall noise background in cities.
Face it guys- the present generation has hardly a clue about the
analog world and no idea of the proud traditions and rich history
of the radio world. Stage by stage, electronic devices such as
radios become increasingly digital. They are doing amazing things
with class D audio amplifiers and such. Often the only remaining
stages of a radio that are still analog are the front ends. Radio
modes themselves are increasingly going digital. To the present
generation, who could care less about our fate, these
incompatibilites between modes are meaningless. Where we
risked life and limb stringing wire antennas, soldered circuits
together, and strained to hear faint signals in the static late at
night,  these folks grew up as couch potatos with TV as child care
and played with video games. There are far more of 'them' than
there are of 'us'. These folks are completely unclued, and we
can not expect that they will ever 'get it' or have any real
sympathy for digital RFI problems.
The Scientific American article in the Feb 2002 issue says that
the prototype units are immune to interference from a vacuum
cleaner plugged into the same outlet and running! Somehow I
doubt that 1.5KW on topband is going to cause any problems.
The sad fact is that the designers *obviously do* understand the
interference implications of what they are designing- otherwise
why would they bother to notch out those 8 channels? They are
certainly smart enough to design in sufficient immunity against
RFI from nearby transmitters. At some level, conscious or
unconscious, there has to be knowledge on their parts as to the
very destructive implications for the radio modes. In the final
analysis, what always moves the world is the almighty dollar
(euro, etc.). There is big money here, and so far fiber has
failed to deliver on its promise of fiber-to-premises
(or premises fiber network interconnects) because of
cost difficulties and a far more serious potential for transmitter
RFI causing major interference. This is the networking industry's
way of dodging that bullet, for now. There is no way on earth
that any radio lobby could kill this thing, as I see it.
I worked for a modem manufacturer in the early 80's, and am
quite familiar with the effort by the FCC and other regulatory
agencies to head off the rising tide of digital interference.
Although they were well-meaning, it was obvious from the outset
that they had no idea just how much RFI suppression would
have been necessary to be truly effective. I bet that all
topbanders have had to deal with multiple interference
sources from switching power supplies, networking cards, and
the like. (Not to mention neighbor interference from the same
types of devices). In a way, I have come to view this as the
military must have in the era of knights in armor. It came as a
rude awakening to the infantry and the cavalry when the artillery
caught up and then surpassed them. Things changed overnight,
and forever. In that light, we are at least blessed with a very
long transitional period. Weak-signal DXing is the mode most
threatened, and not universally- mainly in cities. At this point,
there is still a thriving radio community overall, and it is 
adapting to digital modes rather than being killed off. Radio
promises to survive indefinitely, although in changing form.
I don't think they will ever succeed in totally destroying 'analog'
(human intermediary) weak-signal DXing so long as the
amateur fraternity survives overall. That is the issue to watch,
because ham radio is increasingly threatened on all fronts by
the morally despicable practice of antenna bans, and by
morally despicable laws forced through by lobbying interests,
which hold innocent hams responsible for interference with
shoddily-designed consumer electronics with *no* RFI immunity
against nearby transmitters. This is in clear defiance of previous
rational laws requiring manufacturer responsibility. Money talks. 
Kill off ham radio and all you are left with is a bunch of pirate
wannabe's world wide. These are opportunistic DXers and not
the true experts- they are pretty much unclued as to weak-signal
work, being basically appliance operators and no more.
73, David K3KY

On 9 Feb 2002 at 16:52, Ulli Grunow wrote:

> Hi topbanders,
> Here in Holland consumer electronics discounters are already selling
> complete PLC systems to use your home electric 230V AC wiring for your
> computer network... they are especially promoting that this PLC
> equipment on sales is much easier to install, than usual Ethernet or
> optical wiring for a high speed network - they promote this PLC home
> system to be you home-intranet...
> 
(snip)