[RTTY] TX9 -Reversed I'm confused

[Kok Chen]

On Oct 15, 2004, at 8:55 AM, Art Searle W2NRA wrote:

> He's not listening upside-down!  He's just sending upside-down and 
> that's no big deal, right?.  Just transmit right side up!  Ok I'm a 
> RTTY Rookie and I FSK.  Is this an issue because most ops are using 
> AFSK now?

If by AFSK you mean software modems, then it is an easy matter to swap 
the mark and space tones independently for the receive and transmit 
directions.  If a particular software modem does not support it, you 
might send a note to the author to suggest that is a good idea.  IMHO, 
being able to reverse the receive tone pair from the transmit tone pair 
should be a very prominent toggle switch, whether it is a software 
modem or a hardware modem.

DX sending and receiving with opposite tones happens quite often and it 
is worth practicing ahead of time what needs to be done to work them 
before it actually happens.

There are two separate directives in the Kantronics modems for example, 
one to swap mark and space tones and the other to reverse them on 
receive.  The HAL ST-8000 has a selectable memory right on the front 
panel where you can store inverted mark and space tones, together with 
an independent toggle switch to invert the receive polarity.  So there 
are plenty of examples of good hardware user interfaces for the 
software modems to follow.

73
Chen, W7AY