[RTTY] Pet Peeve # 2
Jerry Flanders
jeflanders at comcast.net
Mon Oct 18 16:54:41 EDT 2004
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 at 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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