[Elecraft] K3 - MMTTY interface for FSK

[N2TK, Tony]

I am having brain freeze. I must have changed something but not sure what.
Both K3's had been working fine on FSK using MMTTY for years. I can still
receive fine, but I can't transmit on either.

I am using LP Bridge which is talking fine to either K3.

When I hit Xmit in MMTTY the program shows it is sending, but it does not
key the K3.

 

All along I have been using COM 1 on my PC for FSK keying. I have been using
pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin 7 (PTT) to Pin 4 on
the K3.

When I measure voltage on Com 1 pin 3 it is -9V. When I hit Xmit in MMTTY it
stays at -9V.

 

MMTTY is setup as follows:

-          Misc tab - COM-TxD (FSK)

-          TX tab - Port Com1.

-          I am not using Radio Command

 

K3

-          PTT-KEY is OFF-OFF.

One K3 has KIO3A using RS232. The other has KIO3B using USB.

 

Also if I ground pin 4 on the Acc socket it does not transmit.  

Tried another Com port and made the change in MMTTY but the same result.

What could I have inadvertently changed so that the Com 1 Pin 3 to stay at
-9V?

 

Tnx for any feedback.

N2TK, Tony