[Elecraft] [KX3] Digital transmissions problems solved finally

[Gary Hawkins]

With considerable help from Don Wilhelm (greatly appreciated), and after 
several conversations with Elecraft I finally solved by JT65/JT9 
transmission issues.  The equipment was PC running WSJT-X/HRD and an 
unmodified Signalink.  WSJT-X was in transmit mode, I could hear the 
tones using the Mon connector on the Signalink, the audio tones were 
making it to the tip of the KX3 Mic connector (used amplified audio amp 
connected to tip and Ring 2), and yet the ALC would not go above zero 
and nothing was being transmitted by the KX3 no matter how I set up the 
mic level and various Windows/Signalink level controls.

The identified problem - I was trying to transmit the test Tone and JT9 
signal above the 2.8KHz upper bandwidth limit on the TX path of the 
KX3.  No matter what you have the RX bandwidth set to, the maximum audio 
frequency that will go through the transmit chain is 2.8kHz.

Hope this information saves someone else a lot of trial and error trying 
to determine what's gone wrong in their digital setup.

73's Gary K6YOA