J.
Excellent plan.
Well documented testing, complete with measurements and observations
from inside YEC, could convince the controlling agencies that any fears
of power grid problems are unjustified. I'm not aware of any similar
tests. Even if your tests didn't convince the FCC directly, it would be
enough of a lever to push for further testing.
Bet ARRL would be interested...
Thanks for your efforts.
Jay, W1VD
----- Original Message -----
From: "J. Allen" <[email protected]>
To: <[email protected]>
Sent: Thursday, December 30, 2004 4:33 AM
Subject: LF: Power Line Carrier gear de VY1JA
John,
I would be quite surprised if Power Line Carrier equipment were
disrupted by
amateur equipment. The power lines are rotated physically to balance
fields
for a number of reasons. It just happens to help prevent line
transmission
of PLC signals and pickup of our LF signals.
Installation, and maintenance of PLCs came under my supervision until
I
retired from Yukon Energy Corp three years ago. If a small utility
like YEC
installs and maintains things with this care, I suspect that the fears
of
power company problems in the populated world south of us are totally
unfounded....
I will find out some of this, because several of the men in my
previous crew
are still with the power company and are all licensed amateurs. My
experiments will be done in such a way that they can monitor my early
transmissions and signal levels (or as I suspect, absence of them) on
the
PLC subsystem.
It is my belief and expectation that this kind of monitoring and
testing can
demonstrate that amateur LF work can cohabit the same neighborhoods as
PLC
SCADA control systems. The 138,000 Volt line which carries the PLC
signals
is approximately 100 meters from the tower which will be the 137 kHz
antenna.
The way the PLC works is that the power transmission line also is used
as an
RF transmission line. The PLC transmitter runs approximately 75 -150
Watts
directly into the line and the line carries that to a matched load of
a
transmitter/receiver pair on the opposite end of the line. With the
high
signal levels that are forced into the line and received on the
opposite
end, I cannot see how the small amount of signal that is picked up by
the
antenna effects of the power line can compare or how it can cause any
trouble.
Has anyone in the UK heard of any LF transmitter causing problems with
PLCs?. If so, I would appreciate knowing the details.
J.
VY1JA
CP20kw
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