[RTTY] Baudot

[W0YR at aol.com]

RYRY is totally meaningless unless you are trying to set the mechanical range 
finder on a teletype MACHINE.

On the mechanical machine there were 5 vanes which were pulled in or left out 
as each character of the Baudot (5 level) code was sent.  With "R" all of the 
vanes were out.  With "Y", all of the vanes were in.   The range finder, a 
mechanical adjustment was moved back and forth over a small range until the 
machine printed RY perfectly.  

This has no counterpart in electronic reading of the Baudot code.   One 
character is all Mark tones and the other is all Space tones.  

The most important thing you can do to be received clearly is to send  TWO 
spaces between each group you wish to print correctly.  That way if one space 
is missed, the system can still UNSHIFT on the second space.   

The other important thing is to set up the "diddle" function.  These are 
synchronizing pulses to keep the receiving system in sync with the 
transmitter.  If your buffer empties and you just send a space tone, the 
minute a "Mark" tone is sent (as copy resumes) your receiving system has to 
say a kind of "ok, what's this?"   Often, if copy is poor the first letter 
will garble on receive when copy is received.  If the transmitter sends 
diddles or syncronizing pulses, this is avoided.

Sending dashes between signal report characters may look nice but they do 
nothing to force the system to recognize the right character.   

Someone the other day correctly suggested putting a <CR> at the start and end 
of every transmission.

This does two things.

1. It gives the receiving system a chance to sync on your Baudot pulses.  
(Without the CR it's much more possible the first letter of your call will be 
garbled.)

2.  It separates your transmission from the other stuff just sent or 
received.

Which is easier to read on the screen?


CQ TEST CQ TEST DE W7YYY KZ7YYY DE UA9MM UA9MM K

or

CQ TEST CQ TEST DE W7YYY K

W7YYY DE UA9MM UA9MM K

The two CRs take about 1/4 second each.  

GL

Mike
W0YR