Re: LF: opera coding demistified

[M0FMT <m0fmt@yahoo.co.uk>]

Hi All

 

Why lock up a PC to beacon Opera? I use G4JNT's excelent PIC progragram. He supplies the Hexadecimal code for you to program your own PIC which gives you just that little bit more satifaction in building a PIC based project.

It is easy to build has full OP modes and sensible and adjustable interval timing, no bigger than a matchbox!.

 

Highly recommended.  http://www.g4jnt.com/OperaBeacon.zip

73 es GL Pete M0FMT IO91UX

From: Markus Vester <markusvester@aol.com>
To: rsgb_lf_group@blacksheep.org
Sent: Monday, 16 July 2012, 23:18
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 

http://rn3aus.narod.ru/opera_protocol.pdf

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

http://df6nm.bplaced.net/opera/opera_generator.zip (24 kB)

 

Best 73,

Markus (DF6NM)

From: Rik Strobbe

Sent: Friday, February 17, 2012 11:48 AM

To: rsgb_lf_group@blacksheep.org

Subject: LF: opera coding demistified

PE1NNZ seems to have demistified the opera coding, those interested can read the attached file.

73, Rik  ON7YD - OR7T