[Elecraft] RTTY and K3

[Dave G4AON]

Hello Lee

You are about right:

Line in/line out are just alternatives to using the front or rear 
microphone socket and work on SSB as well as data.
Data A (short for data audio) is the same as SSB, except that 
compression is forced to zero. You can reverse the sideband by pressing 
and holding "ALT". The dual passband isn't available in this mode, 
neither is text decoding on the K3 screen (trying either results in a 
display of "N/A"). Generally used with any sound card data mode.
AFSK A is used for "audio" RTTY but otherwise is the same as Data A, 
sideband reverse is available, dual passband works and so does text 
decoding. Sending RTTY via the paddles doesn't work on this mode.
FSK D is for hard wired RTTY keying. This mode also allows RTTY keying 
by using the Morse paddle input. Sideband reverse is available via 
"ALT", dual passband works as does text decoding.
I've not tried the PSK D mode.

For hard wired RTTY, the single transistor shown in the MMTTY help files 
works fine.

Perhaps the easiest way to operate the K3 on sound card data modes is 
with Ham Radio Deluxe and DM780 (included with HRD). You only need two 
audio cables to/from the Line in/Line out and a serial cable. HRD keys 
the radio via the serial cable (no need to specify anything special, 
except to set the serial data rate and comm port), the program also 
knows the RF frequency of the displayed tone, so setting your K3 to the 
centre frequency of  one of the Olivia 500 channels doesn't involve any 
head scratching or maths on your part!

73 Dave, G4AON
K3/100 #80
------------------------

I am reading the book here and trying to understand how to set up RTTY 
or PSK with the K3. What gets in my way is the RTTY reading and 
generation algorithm. I am not all that excited about that right now, 
but I am just trying to get my sound card hooked up to the Input and 
Output with PTT as well. Three simple cables and I am sure where all 
that goes.

What is confusing is how to set up the radio. AFSK-A is selected by the 
B Vfo when you use Data MD. So supposedly, the line out audio which goes 
in the sound card will work, but more importantly, the line in of the K3 
will accept the audio generated by the soundcard. I don't have to turn 
on the TEXT DEC unless I want to see the RTTY message on the K3's 
screen. Once I get FSK set up and I would them change VFO B to FSK D.

I think that is right...or have I taken a wrong turn...

Lee