[RTTY] Questions

[Kok Chen]

On Jun 17, 2010, at 6/17    9:33 AM, Tom Martin wrote:

> Why is Fldigi so popular?  Tried many times to set it up and I can't  
> get it to work.

IMHO, in answer to your question, I think there are two primary  
reasons.  One is that it is "cross platform" and the second is that it  
supports many modes.  It is also free (but so are many other software  
modems).

I find more and more hams today either moves between operating systems  
or use multiple operating systems.  fldigi supports Windows, Linux and  
Mac OS X.  Except for little things, the feature set between the  
different versions of fldigi are virtually identical.

On the Mac OS X, fldigi is a multiperson effort while cocoaModem is a  
singer person effort.  (By the way, "fl" = fast and light, and  
"cocoa," in their names refer to the operating system frameworks which  
the two programs are written on).  With cocoaModem, I only implement  
the stuff that I myself use.  I don't use Olivia and MT63 because I  
personally consider their bandwidths to be excessive (but really have  
no problem if someone else uses it when the band is not crowded).   
Because of that, ops that need Olivia and MT63 (and I have had  
constant stream of requests, all of whom I point in the direction of  
fldigi, now that it is available on Mac OS X today).  fldigi supports  
those modes and many more. The same would be true if you are a regular  
MMTTY user on Windows who needs Olivia, although you have a wider  
choice there (MultiPSK, etc).

As to your set up comment, I am not sure what to advise, since I have  
only tried fldigi on Mac OS X.  I don't know what the user interface  
details are for Windows or Linux.

But... on Mac OS X, you need to do two things:  the first, which you  
must do, is to select the Modems menu in fldigi's "Configure,"  click  
on the SndCrd tab to choose the Audio device and Audio settings --  
they must point to the sound card that is connected to your radio.

Second, you need to figure out what PTT mechanism to use to key your  
transmitter into transmit mode.  Many rigs, like the K3 has an active  
VOX circuit in digital modes, and you need not do anything special in  
fldigi, just let the AFSK tone pair trigger VOX for you.  While other  
rigs, like the FT-1000MP disables VOX when in digital modes.  If your  
rig does not support VOX, you will need to use the "Rig" tab in the  
"Configure" menu and either set up an RTS/DTR keyed PTT (through a  
serial port) or perform PTT through the rig CAT commands.

Basically, with software (AFSK) modems, you need to (1) get audio from  
the computer to the radio and get audio back from the radio (the sound  
card interface) and (2) provide a way to key the transmitter into  
transmit mode.

Get those two things to work properly, and you should be good to go  
with fldigi (yeah, you need to make sure the RTTY tone pair of fldigi  
has to match the rig's filter, etc, but you need to worry about that  
even with other programs.

73
Chen, W7AY