[RTTY] fldigi vs the others

[iw1ayd - Salvatore Irato]

Hi Bill and all.
I have no instrumentals or scientific evidences, but let me trow in my 
two cents.

FLDIGI works pretty well. It's better ammunition is the AFSK TX, using a 
K3 it result in a clear and crisp modulated AFSK signal. based on 
reports and pictures by friends.
RXing is pretty well done but I am back within just a month or so and I 
didn't tested it on worst case.

What is pretty amazing about noise immunity, it seems to me, is 2Tone. 
Almost one year and half ago, it was several versions ago, I did a 
pretty well JA RUN on 40m at the late evening here.
For who isn't acquainted to the EU side of the lower RTTY strip of the 
RTTY sub band I could say it is a real nightmare. Our local late evening 
hours are a bandwagon of PSK, CW and more exotic digital signal + 
several different kinds of noise. Slow shifting carriers, some CW like 
manipulations, static crashes and electrical wide band noise, name one 
and be sure you have it or all well together on times.
Our region 1 RTTY sub band have a end at 7040, but 7035 is well used 
from JA. Having a great tooling, a 2 el at 30m from ground, on 40m it is 
the most pure joy when JA comes in. Well, even with the worst Russian 
single letter pseudo beacon in betweens mark and space 2Tone is able to 
make you RUNning as the hell.
I have been there several more times in other RTTY contests since then. 
All the times with two 2Tone windows, one with standard filter and the 
other with flutter filter I'd never miss a call. MMTTY is still there in 
the main windows of the N1MM Logger setup. But it is quite not usable in 
all that noisy, dirty and worst slice of the RTTY sub band.
2Tone continue to steam call by call with even the weakest signal with 
just one tone. TOn times I have to shake myself as I didn't listened  
any RTTY signal BUT one of the 2Tones windows is decoding valid calls 
and writing all those onto the screen. ... One of the two 2Tone or each 
of the two with slight better signals.
So far, it's my personal opinion that in a contest where I don't have 
the time to switch and experiment with MMTTY profiles 2Tone is the most 
self adaptive and thus effective thing - even better than the sliced bread.
BTW I eat a lot of sliced bread ;-) ...
Usually I RUN with K3 and 500 to 300 Hz filters. But also with a IC-7600 
and similar filters = same effect. But even wort audio, of course ...

Back on title, no way for fldigi, even if it is so effective it couldn't 
not run 2 different filters algorithms on the same signal. But, anyway, 
I could try using it together with N1MM Logger ... but running AFSK. on 
pileups.

Another way to think about the same kind of experimenting would be: how 
many time I wish or would engage Dual PBT or TPF?
I suspect quite never with 2Tones as it work better in noisy 
environments, some more hundreds Hertz give the better chances to decode 
even the weakest signals ... I almost forgot that audio enhancing feature/s.
Sorry not to have A/B comparison by now. I will look forward on it.

       73 de iw1ayd Salvo

PS I use almost the same N1MM Logger env. at home when not in PSK with 
FLDIGI stand alone.