[Elecraft] LIN IN level varies

[Alan Ibbetson]

I'm an infrequent user of data modes. I'm trying to use FT8 with the 
latest version of the WSJT-X software. Sound card input is via LINE IN. 
I'm using DATA A mode.

Everything works OK on transmit except that intermittently the K3 output 
falls to zero even though the sound card audio output level isn't 
changing. The VOX stays on, so the K3 is "hearing" the audio. ALC 
usually but not always falls to zero from the 4 bars level. Even 
weirder, if I turn the MIC gain (LINE) down to zero and back up again 
the output and ALC come back up to normal.

Is this a hardware fault? A software fault? Or something even weirder? 
My FW REVS says

uC 05.14
d1 02.83
d2 00.00 (no KRX3 is installed)
FL 01.19
dr 00.00

73. Alan G3XAQ
-- 

Alan Ibbetson
alan at g3xaq.net