The problem I dealt with is not contact bounce, but contacts that do not make a low enough resistance connection to trigger the logic properly. It sounded like that was Werner's problem too.
It's easy to see the contact resistance issue using a scope on the key line. The key voltage simply isn't being pulled down far enough to reliably key the rig unless the contacts are *very* clean, and without adequate current flowing through them to maintain a self-cleaning action, they quickly oxidize again without help - or some other way to key the rig like Vic's clever relay circuit. The K3 is much more forgiving in that respect, but I haven't investigated to see why. IF it works, I'm happy :-) I've never experienced significant contact bounce with a bug. The full weight of the pendulum mechanism is mashing the contacts together as long as the dit interval lasts. The only possible problem can occur on break as the contacts separate, but the "U" shaped spring will prevent that if it's working correctly. As the pendulum moves away from the stationary dit contact, the spring pushes against the contacts, smoothly holding them together until the spring reaches the end of its travel and the contact moves away. If the spring vibrates at all at the moment of break, it will be moving in the direction to further separate the contacts as they part. By the time the "U" spring might swing the contact back back toward the stationary dit contact, the pendulum has separated the whole assembly far enough to avoid the contacts touching. Some fellows dampen that "U" shaped spring so it doesn't move freely. I'd expect them to experience contact bounce since they've defeated the mechanical "de-bouncer". Ron AC7AC -----Original Message----- All you need is a 1uf capacitor across the bug contacts. Radio Shack has some that are small enough to fit in an RCA plug! Actually .5 UF is enough so I have 2 ea. 1UF in series. These eliminate the mushy and double dit symptom. Cleaning doesn't always work. Some modern rigs such as the K3 and Omni 7 are overly sensitive to switch noise and the cap will clear it up. Radio Shack PN is: 272-1434 Steve N4LQ [email protected] ______________________________________________________________ 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
