Update on BPL activity
Owen Duffy, VK1OD
As you know, the Radiocommunications Act makes it an offence to recklessly
engage in conduct that causes substantial interference to radiocommunications
services.
Some people have peddled notions that amateurs are not protected from
interference, but aside from the specific provisions in the current LCD
regarding LIPD interference, the Radiocommunications Act does protect
amateurs from "substantial" interfence.
It may become incumbent on us to build a convincing case of what consititutes
"substantial" interference.
To that end, some of us are considering the feasibility of a survey
of ambient noise levels, particularly on the lower HF bands. Such a survey
will provide us with current knowledge of background noise levels in the
Australian context, a baseline for arguing cases of "substantial"
interference, and a "before" observation in a "before and
after" scenario where interference sources such as BPL, inverter
air conditioners etc are installed.
This is a significant challenge, as we don't have, and can't afford
laboratory EMI receivers and antennas for a full CISPR compliant measurement.
However, amateurs are known for innovation, improvisation, and achieving
results with limited equipment.
Ed Hare (W1RFI) and myself have been collaborating on development of
a software tool to assist in the task of making measurements, calculating
the results, and consolidation of the results from measuring stations
on a
central database.
Phil Wait (VK2DKN) and I have been working on tools for calibration of
receiver bandwidth and noise floor, and calibration of the software of
which I have spoken.
I hope to bring you news of this project in the next week or two.
Meanwhile, we expect that the Australian Communications Authority is
on the ground in Queanbeyan, NSW where Country Energy is conducting a
trial of Mitsubishi 45Mb DS2 based equipment. We look forward to publication
by the ACA of those measurements on their BPL Portal, hopefully in the
coming weeks.
Owen Duffy - VK1OD
Source: Wireless
Institute of Australia
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