Paul and all, We are discussing mechanical contacts that are "dry".
Contact bounce is a "fact of life" and is a problem to be contended with in any "dry" mechanical switch (bug, straight key, mechanical switch, relay, etc.) It can be minimized with sealed mercury-wetted contacts, but without considering the mercuy wetted solution, is a very real problem. When designing a console for a large computer system, I added de-bouncing latches for every switch on the console panel because I knew that even high quality switches had contact bounce. Fortunately, I was able to specify the switches to be SPDT so I could use set/reset latches for the de-bouncing mechanism. Dirty contacts, dissimilar metals and other things of that nature only amplify the problem. *All* switch contact closures will bounce - the question becomes "how long will the bounce condition be present". There are effective de-bouncing circuits that can be used (set/reset latches if the switch is a SPDT), but the most common de-bouncing mechanism for SPST contacts is to sample the switch closure over a period of time (milliseconds), and if the closure exists during and after that time period, it is declared as a valid contact closure. In the case of CW+, the timing must be smaller than the duration of the fastest allowable element (a dit time at 100 WPM - which may be just a "tick")., so yes, some contact bounce timings may be interpreted as valid dits (even though they may be shortened to "just a click" or a "tick"). IMHO, the CW+ option should not be used with bugs and straight keys because they suffer from potential contact bounce. With logic controlled (and already de-bounced) circuits such as keyboard CW and other forms of computer generated CW, there should be no problem. 73, Don W3FPR Paul Christensen wrote: >> "I think that is not being communicated here is, I'm NOT hearing >> "intermittent audible side-tone clicks" I'm here TICKS..." >> > > I am hearing the same "tick" on the leading edge of the side-tone only when > using a bug in CW+ mode. It disappears when CW+ is deactivated. So, > whatever we want to call it, an artifact is there, but I think it's > manageable external to the bug and K3. > > Paul, W9AC > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
