[Elecraft] K3 double beep when not connected

[David Ferrington, M0XDF]

Due to other commitments, I've had my K3 disconnected from everything  
and sitting in it's case for a few weeks now :-(.
I notice every now and then, it gives a double beep. Don't recall  
seeing this described in the manual, can anyone explain what this  
means - other than it reminding me I should be using it!
73 de M0XDF, K3 #174
-- 
We can't solve problems by using the same kind of thinking we used  
when we
created them. -Albert Einstein, physicist, Nobel laureate (1879-1955)