Hi Patrick,

The marine Digital Selective Calling is GMDSS (ITU-R M.493-9 to
M.493-11) DSC. 

Hams are using the "Australian" Selcall (CCIR 493-4), an older version
of this standard, with addresses limited to 4 numeric characters. This
standard is used by Codan, Barrett, QMAC, Vertex, Icom, etc. It is
common to Australian HF 4WD VKS737 system and other services.

I believe the character coding table for the Australian Selcall is the
same for new GMDSS DSC. 

The protocol for CCIR 493-4 is much more simple than GMDSS DSC.
I have bits of the CCIR 493-4 specification, but I do not have the
complete original document. When I get time to upload them, I will
make the specs available on the HFLINK website soon.

Bonnie KQ6XA

--- In [email protected], "Patrick Lindecker" <[EMAIL PROTECTED]>
wrote:
>
> Hello Bonnie,
> 
> Do you mean that it is the same system as GMDSS DSC used for digital
selective calling system for use in the maritime mobile service?
(ITU-R M.493-11 recommendation)
> 
> 73
> Patrick
> 
> 
> 
> 
>   ----- Original Message ----- 
>   From: expeditionradio 
>   To: [email protected] 
>   Sent: Friday, May 11, 2007 10:39 PM
>   Subject: [digitalradio] 100 baud FSK SELCALL Re: RTTY Configurations
> 
> 
>   > Does anyone run 100wpm ASCII RTY anymore?
> 
>   There is increasing use of 100 baud FSK SELCALL in ham radio.
>   This is HF SELCALL CCIR 493-4 (Australian Selcall).
>   HFLINK maintains a database listing of operators using it: 
>   http://tech.groups.yahoo.com/group/hflink/database 
> 
>   It is similar to Marine DSC (ITU-R 493-9) which is also 100baud FSK.
>   It is only used with USB (upper sideband), and 
>   the mark (lower) frequency is fixed at 1700Hz. 
>   It uses FEC, and it is a very robust system.
> 
>   Bonnie KQ6XA
>


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