[UK-CONTEST] RTTY operation (was ARRL Contests)

[Chris Tran ZL1CT]

Hi Steve et al

I think it is OK for our particular set-up to have AFC on when 'running' - I 
probably need to explain more -  myself and Ken ZL4NR had quite a learning 
curve about this - so much so that I'm putting a webpage on my website about 
it, with some screenshots. None of the existing internet help pages were 
sufficiently specific to our set-up.

For RTTY, ZM4A is running N1MM contest logging software, which controls the 
MMTTY datamodes software, which in turn controls the MicroKeyer II router 
software, which then controls the MicroKeyer II via a virtual COM port. The 
MicroKeyer then keys the FSK socket at the back of the FT-1000 MkV.  The 
true FSK this generates means that our RTTY *transmitted* mark and space 
frequencies do not change unless the FT-1000 VFO dial is changed - either 
manually by the operator or by the software via the CAT control (which N1MM 
might be able to do, but we don't really want)  For this reason it is OK to 
use the MMTTY 'AFC' facility and/or the RIT as you suggested, to tune in 
stations that are calling when running. Personally I think the RIT method is 
better than the AFC method.

On AFSK the situation is very different - the software can easily vary the 
audio tones that are sent to the Mic socket on RTTY transmit, hence varying 
the RTTY transmitted frequencies, so with AFC and NET both 'on' the 
possibility of following another station up or down the band is real.

The advantage of true FSK is that it is difficult to have a poor transmitted 
RTTY signal, whereas with AFSK it is easy to overdrive the Mic input stages. 
However, our initial impression is that true FSK has the disadvantage that 
when S&P, you have to carefully tune in every station you wish to call (with 
our AFC off) to be accurately netted (you could argue that their AFC would 
find us but if we're in a pile-up I guess not)   Standing by to be corrected 
by experienced RTTY ops. !

Good luck with GB5CC - I had great fun operating GB5CC last year - hope to 
work you with my new callsign ZL4CT or as ZL1CT. Not sure yet if I'm in the 
VK/ZL team but I'll be QRV anyway.

73
Chris
ZL1CT/GM3WOJ