[Elecraft] K3 w/KIO3B has confusing RTTY transmit behavior

[Joe N9OK]

Hi, I've recently upgraded my K3 with numerous upgrades including a KIO3B
board. I've successfully configured most of what I need but RTTY has been a
problem.

What I see is that I am able to transmit power in RTTY mode if my K3 is set
into *DATA A* mode. If I set my K3 to *AFSK A* mode, the radio has the
appearance of transmitting in RTTY mode but there is no power. IE, TX
illuminates, the ACL meter moves. But Monitor is silent and there is no RF
power. MIC gain is set the same for both modes. VOX is set for both (not
PTT).

The problem first showed up in DXLAB WinWarbler. However, I've confirmed
the exact same problem occurs when I am running a stand-alone MMTTY
executable.

I realize that I could use an external FSK interface. But I"m looking for a
simple setup, and  the documentation I've seen indicates that I should be
able to obtain output power using *AFSK A* mode.

It appears to me that there is an audio routing issue in my K3. However,
that seems unlikely, as others would have reported the issue and it would
have been corrected. What I'm hoping is that there is a simple setup issue
that someone can direct me towards.

Any ideas would be extremely appreciated.

73, Joe N9OK