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Homemade straight key, circa 1990

I completed an apprenticeship as a physics laboratory technician. In the first of the four years we did a lot of mechanical work: turning, milling, etc. I was fascinated by radio and in my spare time, using the machines at my training company, I built a Morse key — probably in 1990.

How exactly I came up with this design I no longer know. I suspect it was through an illustration in a magazine or a visit to a museum.

Wood: beech from a bed frame: 150 mm × 70 mm.

Total weight 720 g — quite substantial.
Knob: cotton fabric reinforced phenolic resin. It smells strongly when turned on the lathe.
Parts made of brass, from brass offcuts I could get for free. The brass parts were nickel-plated and then gold-plated by the company “Werner Flühmann AG, Galvanik mit Edelmetallen, Dübendorf”. As far as I know, this company no longer exists. That was very expensive for me at the time. After gold-plating, the M8 fine thread and all the other threads seized and I had to re-cut them. They probably applied the coating far too thick.
Lever: aluminium. Contacts: taken from a heavy-duty 220 V relay, full silver, then gold-plated together with the brass parts.
The gap was set extra wide for the photo so that the contacts are clearly visible.
In 2026 I added the black wire to ensure the lever has a reliable connection to ground (M2 screw, thick heat-shrink tubing and fine silicone wire routed through the same hole as the spring). The contact via the side steel balls felt too unreliable to me.
Back then, this was the pinnacle of my mechanical understanding — two polished balls as bearings. One could call it a ball bearing, but it is not one in the sense that the balls actually roll. Today I would use small precision ball bearings. Bearings that small either did not exist back then or were very expensive.
Luckily I still had some old audio cables lying around that I could reuse for the Morse key.
Below the knob I also made a disc, so the hand tires less.

In 2026 I retrieved the key from the basement. Inside, the counterweights made from brass offcuts had come loose — the adhesive from back then had let go. I cleaned and polished the surfaces, which were dusty and probably contaminated with spray-paint residue. With an M2 screw and a wire I secured the electrical contact from the aluminium lever. And soon the time will come when I can put this key into operation for the very first time after more than 35 years.

Back in 1990 I could never have dreamed that I would one day simply browse the internet and order a key. That the price would hardly matter to me. That I might hold an amateur radio licence and be able to plug this key into a modern transceiver. That artificial intelligence would help me fix syntax errors in the HTML code of this web page.