Re: [RTTY] Pet Peeve # 2

[Jerry Flanders <jeflanders@comcast.net>]

Hi, Mike

The space character 00100 could actually be decoded in several different 
ways if a single bit were corrupted. But the "A" character is 00011. It 
would take 3 corrupted bits for one to print as the other, so it is 
extremely unlikely a space would be printed as an "A".

OTOH, the character 00011, which prints as "A" in letters case also prints 
as hyphen in figures case. Your example TOOATYATOOATY shows exactly how 
599-56-599-56 prints if the shift character was missed and is a good 
example of why we should NOT be using hyphens, as was mentioned earlier today.

The space character is the same in letters and figures shift cases.

Anybody interested in the Baudot/Murray code can see: 
http://www.dataip.co.uk/Reference/BaudotTable.php
You can see how a single corrupted bit can change a character, and how it 
might print. It also shows the LETTERS/FIGURES correspondence.

I stand by what I said earlier: I think the space is preferred to <CR> 
because it is a separator AND it synchronizes case on both ends if USOS is 
active.

One minor point: it takes TWO characters to send what we think of as a 
carriage return. The <CR> character is 01000 and the  <LF> is 00010.  Both 
characters have to be received 100% OK for it to work properly. Guys that 
have used the old mechanical machines know exactly how quickly it goes to 
pot if the return happens without a corresponding line feed.

Jerry W4UK

At 19:44 10/18/04, W0YR@aol.com wrote:
> NO, that's not necessarily the case.
>
> In a weak signal situation a space is often decoded as an "A".   Look on your
> screen when someone is sending 599 56 599 56  and you will see it variously
> as:
>
>             TOOATYATOOATY
>
> So your call will show up as VKUAWESAW4UK
>
> A <CR> puts you on a NEW LINE, by yourself, away from all other garbage and,
> on some machines, resets the USOS so you get:
>
> VKUAWES
> W4UK
>
> The carriage return <CR> is one of the RTTYer's most useful tools.  A space
> often shows up as an "A."


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