[Elecraft] Straight Key on my K2

[David Pratt]

** Thanks very much, Kevin, that has done the trick nicely! ** At least 
almost.  I still got the problem occasionally with 0.1uF, but putting a 
0.47uF (474) across the straight key has cured the contact bounce 
completely.  The keying characteristics when moving over to the paddle 
do not seem to be impaired in any way.

Although I was reading the list three years ago, I obviously did not 
store that mailing by Ed KG4ARN in my brain RAM.  It is now printed out 
and stored away for future reference ;-)

73 de David G4DMP

In a recent message, Kevin Schmidt <w9cf at ptolemy.la.asu.edu> wrote ...
>I found the suggestion by Ed, KG4ARN (listed on LA3ZA's mods page)
>http://www.ac6rm.net/mailarchive/html/elecraft-list/2003-06/msg00979.html
>to add a 0.1 microfarad capacitor across the straight key or bug worked
>for me.
>
>The time constant for the paddle lines to come back high is set by the
>220 ohm resistor and 0.001 microfarad capacitors in the key lines which
>gives a time constant of 0.22 microseconds. Adding the 0.1 microfarad
>capacitor across the key changes this to 22 microseconds.  This seems
>like a reasonable value to me since a test in the controller should take
>about 2 microseconds; testing both the dot and dash lines sequentially
>should complete in about 4 microseconds.