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RF current was measured as voltage across the resistor. stability. A 3‑letter message was loaded into EbNaut and the
The relay, configured as a reversing switch, was used as a 7‑hour transmission began at 2300 UTC on the 23rd of October.
shamelessly crude and primitive BPSK modulator. In contrast, The following morning in a very matter‑of‑fact email from Paul
it was actuated with more elegance by a Raspberry Pi 3 came the report that the message “VLF” had been decoded.
running Paul’s sophisticated EbNaut software. There was much jubilation on both sides of the pond and within
MRCN. Later, 5‑ and 8‑character messages were sent and
On the evening leading up to the big day, Markus confirmed received, the latter with a bit to noise energy ratio of ‑0.5 dB, a
from my observations that Spectrum Lab and the GPS were mere 1 dB above what is theoretically possible.
collaborating. Paul gave the OK on the phase and frequency
These adventures and similar ones around the world show that
Amateur experimentation and collaboration can yield a practical
VLF communication system. It will be most gratifying to see
many more Canadian Amateurs involved. To this end, MRCN is
looking forward to working collaboratively with RAC and other
Amateurs interested in formulating a proposal for the
consideration of Innovation, Science and Economic
Development Canada to streamline spectrum authorization
below 8.3 kHz. This may lead to an international VLF Amateur
allocation and another new band.
Joe Craig, VO1NA, was first licensed in 1976 as VO1NA and FP0NA
and served as RAC Section Manager for Newfoundland and
Labrador from 1995 to 2007. He writes: “I enjoy DXing on 160m with
37 zones and 212 countries confirmed and on CW with 340 countries
and the CW DXCC Honour Roll. I am a Life Member of the Quarter
Century Wireless Association, the Poldhu and Marconi radio clubs
and a scientist with the Government of Canada researching
interactions between electromagnetic energy and matter. My father
is VO1FB, my wife is VO1RL and my daughter Julia who knows a bit
of CW and a lot of math and physics.”
Figure 5: The brass on birch modulation breadboard.
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