[GreenKeys] AMTOR/SITOR/NAVTXT Protocol

[Don Robert House]

Most of my time in the Bell System and afterwards was dedicated to the  
transmission of digital signals and selection of products to handle  
the transmission including meeting all the applicable standards  
required.  However programming is not my cup of tea.  The small amount  
of BASIC I used to program test equipment was done with the aid of the  
HP text books and assistance from others.

In 1967 I set a record at Illinois Bell Telephone as the only person  
ever to fail every single question on the programming test....

DRH
K9TTY

On 08 Dec 2014, at 1:03 PM, Olaf DL8OBH wrote:

> Peter Martinez, G3PLX did the implementation for us, the Radio- 
> Amateurs, at the end of the 70s
>
> And an eternal memory to Hendrik C. A. van Duuren for his life's  
> work, the development of fault-free digital radio communication and  
> other radio telex equipment, especially in the form of
>
> Telex over Radio  -  "TOR" !!! Later described in the CCIR 476-5 and  
> ITU-R M.625 specification.
>
> (PROCEEDINGS OF THE IEEE, VOL. 89, NO. 10, OCTOBER 2001: Fault-Free  
> Digital Radio Communication and Hendrik C. A. van Duuren)
>
> Have Fun,
>
> Olaf  -  DL8OBH  /  AF0A
>
>
> Am 08.12.2014 19:30, schrieb Chris Elmquist:
>> I found this too (you know, while I was supposed to be  
>> working  ;-)  ),
>>
>> http://www.w7ay.net/site/Applications/cocoaModem/UsersManual/sitorManual/#sitor
>>
>> 	SITOR-B is an implementation of CCIR 476-5 specifications, using
>> 	the same 170 Hz shift as Amateur RTTY, but at 100 baud and using
>> 	synchronous transmission (no start or stop bits). Character
>> 	synchronization is from occasional sync patterns and from
>> 	the structure of the character stream itself. FEC is achieved
>> 	through the use of a 7-bit code, which implements essentially the
>> 	same character set as 5 bit Baudot, allowing single error bits
>> 	per character to be completely recoverable. In addition, each
>> 	character is repeated once in an interleaved character stream,
>> 	delayed from the original character by 35 bits. This repeated
>> 	character gives another layer for error detection and correction.
>>