[RTTY] Unshifted Numbers

[Jerry Flanders]

There are two different character sets used in RTTY - the letters set and 
the figures set. The machines switch back from one to the other by means of 
a shift "character". For instance, if the figures shift is missed, you see 
TOO instead of 599.

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 (how it will print if the 
shift character is missed).

Jerry W4UK

At 22:01 2/14/2005, NB1B wrote:
>Being a relative newbie to RTTY contesting, I made (for me) a startling
>discovery this weekend.
>
>After continually receiving PPQ in response to my "NR? NR?" inquiry, I
>discovered that "PPQ" is the same as "001".   After operating for 24 hours,
>it seems like the following letters equal the numbers:
>P=0
>Q=1
>W=2
>???=3 (never did figure that one out)
>R=4
>T=5
>Y=6
>U=7
>I=8
>O=9
>
>That "TOO" I see on my screen didn't mean that I also got a "599"- it was
>the "599".
>
>What mechanism makes some programs send the letters instead of the numbers?
>I don't think the problem was on my rx end when someone would send me "TOO
>PPQ PPQ", I'd ask for the number, and he would repeat the same string of
>letters a second time.   What actually clued me in to this was a station
>would send "599 PQP 010", so I'd ask for the number, and he'd send "599 010
>PQP" back.
>
>Dennis NB1B
>