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Surely the concept is not limited to five-letter
words. The current encoder implementation on Paul's website takes up to 50
characters, so you can announce a whole litter of kittens including their names,
colours etc ;-) The coding for longer message actually becomes more
efficient, due to a bit of fixed overhead (constraint length K, CRC
check).
Although the transmit
part is comparatively simple, the decoder is certainly not trivial.
This is currently in an early state of experimentation, and I have no
idea weather Paul would really intend to take it all the way to
an easy-to-use software package for everyday use.
Best 73,
Markus
Sent: Sunday, May 11, 2014 12:37 PM
Subject: Re: VLF: Coherent BPSK at 8270 from DF6NM
Hi Markus,
Uuuh, chatting with max. 5 characters will become difficult i think :-)
As in JT-9, there should be 13 characters, so one can at least write "i have a
cat"... :-)
Well, what does one need to arrange such a decoder? How is
the message displayed? Is it possible to run a detection window, as a text file,
like in OPDS?
73, Stefan
Am 11.05.2014 12:30, schrieb Markus
Vester:
Stefan,
yes, you guessed right, the message content was
indeed "DF6NM" ;-) Let me cite from a recent direct mail to
Paul:
>> I was using a somewhat guessable
message, foreseeing a possible "official first" demonstration. Maybe
a truely random message would have looked even more impressive ;-)
Anyhow as this is formally not "amateur radio" but rather using an
unallocated frequency range, so there's no need for an
allocated callsign. Maybe if you'd set up a transmitter (relatively
easy) and I'd learn how to decode (the hard part), we could start chatting
away on VLF ;-)
73, Markus
Sent: Sunday, May 11, 2014 12:06 PM
Subject: Re: VLF: Coherent BPSK at 8270 from
DF6NM
Hello Paul, Markus,
Well done! Interesting stuff. I see
you never stop to find some new
things to try :-) Well well, i should
think about...
What was the contest of the message? A complete
callsign, DF6NM?
73, Stefan
Am 11.05.2014 08:36, schrieb Paul
Nicholson:
...
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