[RTTY] Minus sign to space serial numbers

[David G3YYD]

I wonder how many of you who use this technique realise why it is not a good
idea?
 
The - (minus sign) is 1 corrupted bit away from 3, 2, \ and Line Feed. So a
1 bit corruption will often result in a repeat request.
 
Space character a 1 bit error goes to  , (comma), ' (quote), #, NULL (5 bits
of space tone). Much better to use space as human can see it and work out
what the serial number is. 
 
2Tone avoids the NULL error as that is mapped to space character. Been like
that for years. NULL is also known as BLANK.
 
So better to send 599 1234 1234 than 599-1234-1234
 
73 David G3YYD