Opera 1: 0.256
s
Opera 2: 0.512
s
Opera 4: 1.024
s
Opera 8: 2.048 s
Opera
32: 8.192 s
To:[email protected]
Subject: Re: LF: opera coding demistified
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 four 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
