[Elecraft] K3 - RTTY Question

[Fred Jensen]

RLVZ at aol.com wrote:
> This weekend I used my K-3 on RTTY for the first time.  Using the  K-3's 
> AFSK-A mode along with N1MM & MMTTY.

Hmmm ... I must be oversimplifying something:

In the K3:
1.  Select DATA
2.  Hold DATA MD and select A
3.  Hold PITCH and set it to 915 Hz [one of the choices]
4.  Set RIT on
5.  Set the DSP WIDTH to about 300 Hz
6.  Turn the VOX on if you aren't using PTT from the CAT.

I did this once and it held for all bands.

MMTTY:
A.  If you've got the CAT hooked up, MMTTY should get the 915 Hz in 
MARK.  If not, set it to 915 Hz.
B.  Set AFC off and leave it off [it will drive you nuts]
C.  Turn NET on and leave it on [makes you transmit where you receive]
D.  UOS on [if you get stuck in FIGS, the first space will unshift]
E.  I use the FIR demod in MMTTY and have the tap set at 128.

N1MM Macros:
1.  Start all with {TX}{ENTERLF} except the one for {WIPE} [F12 for me]. 
  This keys the transmitter and starts you out on a new line on the 
other guy's screen.

2.  Except for CQ and QSL macros, end each macro with a single space and 
{RX}

3.  End your CQ and QSL macros with a single space followed by 
{CLEARRIT}{RX}.  If you used the RIT, that will clear it.

The single space assures [almost always] that the garbage that the other 
guy will print when you drop your carrier is separated from the last 
thing you sent by one space.  Avoid {ENTER} and {ENTERLF} at the end, 
they'll cause your call to march up the screen and the other guy will 
have to chase it with the mouse. [Tnx K6XX]

Remember that Baudot has two cases *using the same 5-bit codes*. 
Letters are in one case.  Numbers and punctuation are in the other case 
[SPACE, CR, and LF are in both].  N1MM macros take care of the case 
shift [LTRS/FIGS] but ... if you configure your exchange macro with 
punctuation such as: {TX}{ENTERLF}N6KR DE K6DGW (QSL TU) (599-CA) 
(599-CA) {RX}, you're adding a lot of FIGS-LTRS pairs and increasing the 
probability that your Q will get stuck in FIGS.  I got an exchange in 
the NAQP RTTY that looked like that.

I use 915 Hz for a couple of reasons, the biggest is that I can hear it. 
  I'm deaf above about 1100 Hz.  Remember that RTTY is really FSK 
between two RF frequencies separated by 170 Hz.  That's FM, and it 
produces sidebands [you can see them as as a forest of dots between the 
two lines in the MMTTY I-Q display].  I find that 300 Hz is about as 
narrow as I want in order to pass the sidebands.  MMTTY will print 
strong signals at 250 Hz or even 200 Hz, but it won't do weak noisy 
ones.  At 300 Hz width, the K3-MMTTY combo will print signals I can't 
really hear, I can just barely see them on the waterfall.

Oh, I didn't realize it at first, but the RIT rate is linked to the main 
tuning rate.  I use a 1 Hz rate in S&P [since I don't ever need RIT]. 
If I CQ at the 1 Hz tuning rate, the RIT rate is way too slow, so when I 
go to RUN mode, I tap the FINE button to a 10 Hz tuning rate.

I've also used my K2 for RTTY once I found out there is a fourth bank of 
filters for RTTY.  Works great!

73,

Fred K6DGW