[Elecraft] K2 dual keying problem

[David Pratt]

Thank you, Don, for your technical description as to what might be 
happening.

I have polished my straight key silver contacts and replaced the diodes 
with 1N5821 Schottky diodes, but am still getting the problem 
occasionally.

It does look as though I shall have to fit a separate jack to the 
straight key and change the InP menu setting to HAnd when I want to use 
the straight key.  I had hoped to have avoiding doing that.  Perhaps I 
shall try and to get hold of some 1N5711 diodes and see if they are any 
better.

73 de David G4DMP

In message <NGEDLJLDCGJIHEGPMIJPMELCECAA.w3fpr at earthlink.net>, Don 
Wilhelm <w3fpr at earthlink.net> writes
>I would rather speculate that it is a uP timing situation coupled with
>contact bounce at the key and the forward voltage drop of the diodes.  If
>one of the diodes is a bit slower than the other, the voltage seen at the uP
>pins may actually look like one pin has gone to a low state before the other
>(that is the condition to generate the iambic alternating dots and dashes).
>This problem can be caused by contact bounce at the hand key - cleaning the
>hand key contacts will help, but one can never cure contact bounce at a
>mechanical closure point.
..........