[RTTY] Unshifted Numbers

[Jeff Stai WK6I]

hi Dennis - welcome to RTTY contesting! I went through the same thing when I 
started, and understanding what is happening here will help you reduce your 
number of fill requests by a whole bunch.

Take a look at your QWERTY keyboard and look the correspondence of numbers 
to the letters immediately below and to the right:

1 corresponds to Q
2 corresponds to W

and so forth. All numbers in RTTY (and a few others characters) are 
preceeded by a SHIFT character, which causes a Q bit pattern to be 
interpreted as a '1' instead. This was done to fit letters, numbers, and 
punctuation into a 5-bit code (only 32 combinations). This is also why you 
saw letters instead of numbers: if the SHIFT gets obliterated, that's what 
you see. You'll also see the letter 'A' instead of a space for the same reason.

Find a table of Baudot characters and study the bit patterns - I usre hope 
there is still one in the back of the ARRL Handbook!

Once you master this, you will ask for fewer fills because you will see the 
letters and know what they mean. For example, you know that:

NB1B TU TOOAPQWAPQWAPQW

is a report of 599 012 012 012

And now you should know which letter corresponds to '3' ;-)

hope this helps! - jeff wk6i


At 02:01 PM 2/14/2005, NB1B wrote:
>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. 

--
Jeff Stai               jds at twistedoak.com
Twisted Oak Winery      http://www.twistedoak.com/
Rocketry Org. of CA     http://www.rocstock.org/
Amateur Radio           WK6I