Hi Joe.

I have to confirm what Parick wrote. I am working on
Olivia/Contestia/RTTYM for PocketDigi and after doing what Patrick
described I was able to send/receiver contestia.

I am using Pawel's code, but I removed a lot of dead code before I
started to understand it. I am affraid you would not want to use my
code directly because it uses fixed point arithmetics, which is not as
 precise as the original floating point code.

73 and GL, Vojtech OK1IAK


--- In [email protected], "Patrick Lindecker" <[EMAIL PROTECTED]>
wrote:
>
> Hello Joe,
> 
> What is sure is that there is no other differences that the ones I
gave in the "RX/TX modes selection and their descriptions" chapter, so
modifications on:
> * Block size (symbols)
> * Scrambling pseudo-random sequence
> * Scrambling shift (in number of bits of sequence right rotation)
> * Characters set 
> 
> Try first to change from Olivia to Contestia. It is the simplest, as
RTTYM adds a switch management, contrary to RTTYM.
> 
> Then try in reception generating Contestia, without noise. You must
decode it. Then adjust the different parameters of your code to decode
low S/N Contestia signals.
> 
> 73
> Patrick
> 
> 
> 
> 
> 
> 
> 
> 
>   ----- Original Message ----- 
>   From: Joe Veldhuis 
>   To: [email protected] 
>   Sent: Wednesday, September 27, 2006 6:38 PM
>   Subject: Re: [digitalradio] Re: Implementing Contestia/RTTYM,
could use some advice
> 
> 
>   Patrick only gave an outline of the differences between Olivia and the
>   derivative modes. What I am looking for is some pointers on the actual
>   task of modifying the templates to implement those differences.
> 
>   I tried implementing RTTYM by changing the "BitsPerCharacter" and
>   scrambling code/shift parameters in Pawel Jalocha's reference code
(and
>   then passing the output through a Baudot>ASCII routine), but that was
>   apparantly not enough, since I don't get any output from the
demodulator.
> 
>   -Joe, KD8ATU
> 
>   jhaynesatalumni wrote:
>   > I haven't looked yet, but you might look in the MultiPSK
documentation,
>   > since Patrick recently implemented those modes in his program
and may
>   > have written them up.
> 
> 
>    
> 
> [Non-text portions of this message have been removed]
>

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