I've often had trouble keying modern solid-state rigs cleanly with mechanical bugs. I've tried various electronic debouncing schemes, with more or less success.
The simplest solution is to use a reed relay -- radio shack has a 12-volt one that works perfectly with a 9-volt battery. The battery lasts for months. Put an electrolytic capacitor across the coil to soak up the bounce pulses. I used 10 uf, I think. Without the capacitor the reed relay is fast enough to reproduce the bounces. You'll have to readjust your bug, since the circuit will lengthen the dits. Problem solved. On 6/19/2010 6:45 PM, Paul Christensen wrote: > I just dusted off my Vibroplex Champion and tried testing with the K3. The > reports of intermittent audible side-tone click are correct in CW+ mode, > although the click can be heard on either dits or dahs, depending on the > degree of contact bounce. I was able to easily replicate the side-tone > clicks by moving around both bug contacts. > > I am using K3 F/W 4.03. First, I tested the bug by plugging it directly > into the K3's rear panel "KEY" input to confirm the issue. Next, I plugged > the bug into my external keyer with a modified Schottky gate/2N7000 > combination. Then, the output of the keyer was plugged into the K3's KEY > jack. The Schottky buffer functions as a contact de-bouncer and ensures > that each contact results in the 2N7000 FET going to ground and no state in > between ground and +Vcc provided by the K3's key input line. The input > buffer cleans the bug contacts, resulting in no audible side-tone click. > > As an alternate to the Schottky buffer, some bug users may want to try > placing a tantalum or electrolytic cap (e.g., 0.1uF - 0.47uF) across the bug > output terminals, observing correct polarity. Tests awhile back showed this > helped with contact bounce, but not the pseudo-diode condition created by > contacts of dissimilar metals as earlier discussed by Joe, W4TV. > > I sure wouldn't want Elecraft to in any way compromise CW+ as it presently > functions. As Guy points out, it may be a byproduct of the new ultra-fast > QSK and as such, other methods of contact de-bouncing can be used when using > a bug or straight key. > > If an external keyer is used with the K3, the first thing I would try is to > plug the bug into the keyer and set it for "bug mode" and use its internal > contact buffering capabilities to ensure that the K3 sees a clean On/Off > state for every contact closure. Some keyers utilize a second input just > for straight keys and bugs and don't require the operator to change the > keying mode through the keyer's menu. > > Anyway, these methods may be worth a try, starting with a cap or an external > keyer. If the problem persists, it may require a more robust de-bouncer > like the Shottky gate type I'm using. > > Paul, W9AC -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ 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
