** 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 <[EMAIL PROTECTED]> 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.
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