[RTTY] K or carriage return

[Kok Chen]

On Feb 15, 2011, at 2/15    6:56 AM, Bill, W6WRT wrote:

> Has anyone here ever operated a contest with MFSK or other
> error-correcting modes? It would be fascinating to see the actual
> tradeoff between speed and accuracy.

My gut feeling is that for stations that are running high power, RTTY  
will be better, since power will help compensate for the reduced  
sensitivity.  You can run so much power that even under QSB, the  
weakest point of your signal is still way over the RTTY decoding  
threshold, for example.  You can repeat until enough of your exchange  
gets through for the other end to log.

But if you are running 25 watts into a dipole?  I suspect that CQ'ing  
in DominoEX will be produce more callers.

One thing to keep in mind though, is that some of the better modes can  
print a signal even when it cannot even be seen in a good waterfall.   
So how would an S&P station find a weak CQ'ing station?  You cannot  
see them in a waterfall much less hear them :-).  There is some cases  
where you don't need that extra sensitivity.  Take a look at the top  
waterfall here

http://homepage.mac.com/chen/w7ay/cocoaModem/UsersManual/mfskManual/mfskManual/dominoex.html#weak

That signal prints so close enough to 100% that you have to wait a  
long time for an error hit, but yet it can barely be seen on a  
waterfall.  The question is therefore, for something like a contest,  
is the extra precision even needed.

As PSK125 contests have shown, exchanges in other modes can be fast  
and adrenaline producing.   However, like RTTY, the PSK31 family has  
nothing to help slow QSB, so does not work worth a plugged nickel when  
conditions deteriorate.  With RTTY, you can at least jack up the power  
to get through selective fading and flutter.

Also, some of the "slowness" that one perceive with PSK contesting has  
to do with the awkward exchanges from some of the operators since they  
attract many non-contesters.  If many people start sending you dots  
and the color of their dog, average RTTY exchanges slow down too.

Just my humble opinion and worth the two pennies.

73
Chen, W7AY