CWTouchKeyer’s P3K Touchkey (Kit Build)

This is an interesting project for the CW enthusiast and home constructor.

The CWTouchKeyer P3K Touchkey

Bought from CWTouchKeyer in the USA, the P3K is a Touchkey kit that is supplied as a small PCB plus the appropriate components. There are lots of other versions available, too.

The kit is constructed and has to be installed into a small enclosure of your own design, out of which project two metal touch ‘Paddles’ in order to operate the key. This is a touch-operated key only, which is designed to be plugged into a keyer, either a stand-alone unit or the keyer that’s built into a transceiver. As the name suggests, only a touch of each paddle is required for the circuitry to produce the switching actions that would generate the Dits and Dahs in the keyer. Therefore, it has an incredibly light touch. There are no moving parts.

I chose to build my key into a readily available Maplin project box. The paddles are solid brass ‘Yale’ type front door keys, donated free-of-charge by a local locksmith once I had explained what I was trying to achieve. Using door-keys is not an original idea, but the ones I used have the benefit of being labelled British Made – a nice touch.

The keys are recessed into a small block of wood (the key block), with each key being set in P38 car filler and then drilled through and bolted through with nylon fixings. The key block has two grooves at each end, cut in with a full-size hacksaw frame carrying two blades at once. This allows the key block to be slotted over the extrusions inside the project box, making it very secure. Small woodscrews were added for rigidity. Slots need to be cut for the two keys in the side of the project box. The wiring is simple, with direct soldering of wires to the two brass keys, and there is enough room for a PP3-type 9V battery, an on/off switch, and an on/off LED on the cover plate.

The photos show the build process from the completion of the circuit board onward.

CWTouchKeyer has further details with specifications, current prices, etc.
At the time of publishing, this website is no longer available).