[Elecraft] K3 Question: AFSK-A or DATA-A for RTTY?

[Don Wilhelm]

Jim, and all,

Yes, the AFSK A data submode is optimized for RTTY operation.  The 
default sideband is LSB and the use of the dual filter is possible. 
Furthermore, the K3 dial display shows the mark frequency.
If you are using an RTTY mode with an application such as MMTTY, you 
will find the AFSK A mode useful and tuning will be done using the K3 VFO.

OTOH, if you are using an application that has a waterfall display and 
does point and click on the preferred signal (rather than tuning to the 
signal with the K3 VFO), then the use of DATA A in reverse mode will 
likely be more useful to you for RTTY - your application may switch 
sidebands when RTTY is selected - check the documentation for your 
application, it is a 'mixed bag' and some application 'do it right' 
without explicit actions by the user while others will require that LSB 
be explicitly selected.  The frequency display on the waterfall is also 
application dependent.  Refer to the application documentation to assist 
in understanding what is being displayed on both the transceiver 
frequency display and on the waterfall.

For data modes other than RTTY, yes, DATA A should be used - it all 
depends on the data mode application.

73,
Don W3FPR

On 9/15/2014 10:07 PM, James Bennett wrote:
> I've been a PSK31 user just about ever since the mode came to be. Not a heavy user, but couple time a month I get on and have some nice keyboard QSO's. In the 50 years that I've been licensed, I have NEVER made a RTTY QSO! However, it does intrigue me so I started messing with it a little this week.
>
> I recently got a new external sound card for my station - a Tascam US125. It is connected to my iMac via USB and the K3 via a pair of stereo cables. Works fine on JT65, JT9, and PSK31. I use WSJT-X for the JT-modes and cocoaModem (CM) for PSK31. CM also provides RTTY so I gave it a shot. After a few burps I got it going.
>
> With PSK31 and the JT-modes, I've always had the K3 in DATA-A setting. RTTY "seems" to work in either DATA-A or AFSK-A. Fred Cady's K3 book states that AFSK-A is "optimized for RTTY". How? What is the real benefit to switching to AFSK-A mode for RTTY? Is that what everyone is using, or is DATA-A just as good?
>
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