[NCC] HELP !!! w/ K3 / N1MM / 2 Tone / RTTY Setup

[Andrew Flowers]

Hi Ken,

> I would like to try 2 Tone (which I am told receives better than MMTTY) but it doesn't interface with WriteLog.

According to AA5AU it does integrate into Writelog as of this past March, but I have no experience with it:

http://www.rttycontesting.com/writelog/xmmt/xmmt-2Tonesetup.html

>  I would like to transmit using MMTTY and EXTFSK, but I have read that this doesn't work with Windows & 2 Tone and will produces an erratic keying wave forms.

Where did you read that, out of curiosity?

The "erratic waveform" one can get with EXTFSK is a result of EXTFSK itself and always has been.  The bit banging of then serial lines is at the mercy of the Windows task scheduler, which under ideal circumstances will give you +/- a couple ms accuracy in the bit boundaries (or in the ballpark of 10%).  Start running other software and doing things like swapping windows or other kernel intensive processes and all bets are off.  Add in a USB serial converter and you get some USB delays too.  On my Dual core 2.4G marching all I have to do is swap between my logging software and notepad and I can make it stutter to the point of missing bits completely.  My P4 doesn't have nearly the same issues, so this is all mystery meat in the processor and OS, and likely the drivers.

Some people swear they need a winkeyer to get readable CW and some have no problem with the bit-banged CW from the serial port.  My guess is that this is a manifestation of the same issue. With RTTY it's a little more subtle, since clock jitter effectively reduces SNR at the receiver.  You might not hear it, but it probably increases misprints and repeat requests over the course of a contest. 

> At this point I am pretty much totally confused as to what to do and how to set up N1MM. I suspect the first setup would be the Master D! window using FLdigi for transmit, a second RX window using 2 Tone for receive, and possible a third RX window using MMTTY for receive, but as I said, I'm pretty confused at this point.

If you are comfortable using EXTFSK, I would suggest that you get TX/RX working with MMTTY with EXTFSK in the main DI window.  Once you have that working you can add on the extra receive windows, which can be 2Tone windows or MMTTY if you want.  I find N1MMs way of setting this up a bit wonky, but I works once you get there.  I can probably offer a little help offline if you can get this far and get stuck.

I'll just mention that the K3 is about as idiot proof as it comes when it comes to AFSK from the soundcard, so long as you enable the AFSK filter in the config menu.  See here for graphic images of me trying to transmit garbage with my K3 (viewer discretion advised):

http://www.frontiernet.net/~aflowers/k3_afsk/

Maybe that is an option for you, maybe it's not, but I thought I should mention it since you said you have a K3.  If you run FSK-D I suggest you are on the latest K3 firmware, as they de-clicked the waveform significantly.  (The above article was put together before the firmware enhancement.)  It was this recent firmware improvement that made FSK-D a viable option for us at W2FU for the first time in CQWW this year.

I hope that helps,

Andy K0SM/2