[Elecraft] K2 key autodetect problems

[Chip Stratton]

I have the external circuit using two diodes to allow the K2 to detect when
a straight key is used instead of the paddles. Occasionally with the paddle
plugged in but not keyed, the K2 will  spontaneously start sending a string
of dashes. This will terminate, sometimes only briefly, when I do key the
paddle. It happens even when K2 transmit power is turned all the way down,
and I've never had trouble with RF in the shack.

Both diodes test fine, at 0.64V drop forward, and no detectable leakage
reverse. The paddle also tests fine, both lines open when it isn't being
keyed, and likewise the autodetect box shows no shorts to the ohmmeter.

Ideas?

73
Chip
AE5KA