Mine showed up today. Seems to work reasonably well up to 25 wpm or so here in the shack. As the website says, it does not require a power source, i.e. no battery, no power stolen from the rig, etc which is interesting and is probably the main reason I bought the thing. Just plug it in like a mechanical key and it works. As SA2CLC says, fingers need to be slightly moist for it to work well but you can accomplish this by blowing lightly on them. It does not work at all with my gloves.
It comes with black shrinkwrap over the circuitry so I cut that off and took a look. All surface mount, very simple - 2 caps, 2 resistors, 2 diodes and 2 “TR8” transistors (small signal mosfet) so presumably 1 set of 4 parts for each touchpad. No capacitive “sensor” chips of any kind.
Looks like each touch pad consists of a series of closely spaced parallel traces with 2 leads per pad running up opposite sides of the pad and connecting to alternate pad traces.
Not sure exactly how it works but I’m guessing the parallel traces on one pad alternate between gnd and “dot” while the parallel traces on the other pad alternate between gnd and “dash” and the pad’s mosfet senses in some way the reduction in resistance between traces that occurs when the pad is touched by a slightly moist finger and effectively grounds the line from the rig.
Anyone got any comments on how it works?
I’m going to give it a try on my next activation but will bring along my trusty “paddlette” key just in case.