Stefan Schaefer wrote
> G.., i have done
it. Downloaded ... to my LF PC. Still can't
belive it...
... well, I haven't ;-)
Out of curiosity, I have instead
implemented Guido's excellent guide on Opera
encoding
in a little Basic program,
which outputs the 110... keying sequence for
any given callsign.
And it
works! For a quick on air test, I decided to
use SpecLab's test signal generator,
modulated by an arbitrary waveform which can
be loaded from a text file. To fit to the
required data format, I edited the sequence
by zero-padding from 239 to 256
symbols, then replacing every "1" by two
lines of "32767", and every "0"
by two lines of "0", giving 512 samples
total. For "Op4" speed, the AM
modulator period was set to 0.256*4*256 =
262.144 seconds. Audio output was used to
key my TX on 478.63 kHz. I sent for
strings on Saturday night 21:30 to 21:47,
and within a few minutes, pskreporter.de
showed spots from DF2JP, G8HUH, ON6EO and
DD7PC.
In case
you would also like to send Opera without
"his master's software", or
associate obscure received sequences with
possible candidates, the little program and
sourcecode is at
Best 73,
Markus (DF6NM)
Sent: Friday,
February 17, 2012 11:48 AM
Subject: LF:
opera coding demistified
PE1NNZ seems to
have demistified the opera coding, those
interested can read the attached file.
73, Rik ON7YD - OR7T
