[RTTY] CAP letters on or off?

[Kok Chen]

On Dec 26, 2010, at 1:35 PM, David VE3VID wrote:

> Sorry about the simple type question.  I'm a bit confused by something I read a while back.  Should I have my computer keyboard CAPS LOCK set on for RTTY?   Otherwise avoid shifting between upper & lower case letters?

There is no case distinction in Baudot RTTY.  Everything is transmitted as a single case.

Your software may display what you type as upper and lower case, but it is going on the air as a single encoding.  Most Baudot RTTY software will print the received characters as upper case.

ASCII Radioteletype allows you to distinguish between upper and lower case, so will PSK31 and other Varicode based digital modes.

In the case of ASCII Radioteletype, there is no advantage either way.  In the case of PSK31 and modern digital modes, it is better to transmit with lower case, since lower case characters are encoded as shorter Varicode that will result in faster data rates, and given the same bit error rate, will result in fewer errors per character.

By the way, they are called "cases" because the old typesetters' movable types are usually separated into different boxes or "cases."  One box (case) contains the capital letters and the other box contains the non-capital letters. 

73 es HNY
Chen, W7AY