"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."
"...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."
David and Ulli,
I believe that you're generally correct in what you say about the PLC
threat to low-band work and about threats to ham radio in general.
There isn't much public awareness of what we do, and we've got to be
vigilant if we want to preserve our hobby.
We also need to remember that ours is not the only service that's
threatened. This month's issue of Compliance Engineering News (I'm
and EMC regulatory enginer) has a report on steps the UK is taking to
deal with the interference which PLC systems have been observed to
cause in that country. (See
http://www.ce-mag.com/archive/02/01/newsline.html) This has affected
"Safety-of-Life" systems, and so they have drafted rules under the UK
Wireless Telegraphy Act of 1949. They're threatening an immediate
shut-down of "interference sources" where the regulations are
breached.
Their approach addresses much more than PLC systems, and this is
significant. Although PLCs are bad, we've got to remember they're
only one of a number of competing systems being promoted for moving
digital data. The phone company's DSL technology transmits high-speed
digital data on RF carriers over twisted pairs. When the line becomes
unbalanced, it radiates. Friends in Austin have told me they can tell
which blocks have DSL services because the radiated emissions open the
squelch on their 2 meter radios.
In the microwave region, Bluetooth radios are supposed to become
ubiquitous. There's a story circulating about a company in Dallas
that tried to use Bluetooth to move data between some buildings and
was foiled by a couple of ham ATV repeaters. They complained to the
FCC and were told the ham systems were legal. Then, laughably, they
tried to buy the repeaters to get them off the air. They had no clue
as to what hams do our how they do it.
Competition for spectrum is going to continue. Not all the players
are going to know what they're doing. There aren't enough good RF
people to go around. We're going to have to live in this environment
and "earn our spurs," as we say in Texas. After all, what reason do
we have for thinking that the spectrum should remain as clean and free
of threats as it was in 1930. I'd suggest that while we should
exercise whatever rights we have to keep sloppy users and technologies
off the air, we should also explore new ways to continue DXing and
Contesting in the presence of these new threats.
One last thought: The Brits are being challenged by the European
Commission, which probably sees the business opportunities in
expansion of digital services as much more important than the need to
preserve a few radio services. After all, who needs the broadcast
services? Everything is going digital, isn't it?
The battle over these sloppy technologies is going to be fought by far
bigger players than we are. We're not alone. It's paranoid to think
we're the only ones who're affected. It makes more sense to look for
allies and to work on technologies which allow us to do what we do in
the midst of all the interference. We claim, after all, to understand
communication and communication technology. Let's do what we do best.
73,
Brad, KV5V
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