Monday evening – Well, my fellow key fanatics, I am now the proud owner of what is one of the most unique semi-automatic keys I’ve seen; it certain is the most unusual key I own. Is it rare or collectible? I’m not certain about that. It isn’t a Melehan Valiant or anything quite that rare. However in my book, it simply oozes with uniqueness, if that’s possible.
There’s no ID tag or serial number to denote its age or maker. Not even a callsign of a former owner. I’m left wondering if it is truly a homebrew key or perhaps a low-production commercial key. Take a look at the photos and tell me what you think (click any of the images to enlarge).
The key arrived in today’s mail, and I’m still trying to determine the intended purpose for all the levers and how to make the necessary adjustments to operate the key. The engineering behind the key is simply magnificent … I may be all wet, but this key strikes me as being European in origin.
For example, the springs for the lever return aren’t coils, but leaf springs — for both the dash and dot levers. It takes a complicated mechanism to setup leaf springs for these purposes — more than the standard Vibroplex takes.
The most obvious addition to the key is the smaller straight key on top of the bug’s pivot frame assembly. The straight key contacts are at the rear of the keying lever, and electrically connected to the “hot” terminal of the key. The spring return for the straight key is a coil spring mounted below the rear of the straight key that applies downward pressure on the lever pulling it back down after it has been keyed. The gap of the straight key contacts are fully adjustable, as is the throw of the straight key lever. And frankly, I’m not really certain if it is a straight key or just a momentary contact switch designed for a specific purpose outside sending Morse.
NOW FOR THE BUG … The operation of the bug is fairly straight forward with some very interesting differences from the “typical” bug setup. Let’s look at the adjustments.
1. This lever operates as a circuit closer.
2. This screw and locknut adjust the dash lever tension. Directly to the right of this adjustments you can see a metal leaf spring. Turn the screw in and it increases the return pressure on the dash lever.
3. This is the right-side “stop” adjustment for the keying lever.
4. This is screw adjusts the tension on the return spring for the dot keying lever.
You can see the pivot point adjustment and the details of the assumed straight key, along 
with its adjustments.
THE OTHER SIDE. Three of the four of these adjustments are the same as those found on a conventional bug: Adjustment 2 is the dash contact adjustment; No. 3 is the stop the keying lever his to make dots; and No. 4 is the dot contact adjustment. No. 1 is a spring-loaded momentary contact lever that slides from left to right. I’m not sure what it was used for on this key as I haven’t tested it electrically to see what circuit it might close. Since it is spring loaded, I doubt it doubles as a circuit closer.
While I haven’t written much about the top mounted straight key, from the side views you can pretty much see how it operates.
Another unique feature on this key is the adjustable damper. See the adjustment screw on the left side of the photo at right? The screw connects to a cam (you can see it isn’t a round shape), and the cam allows you to adjust the vertical placement of the damper. You can adjust the damper up and down, depending on the lever. You want the 
lever to hit the damper correctly; this adjustment gives the user complete control of how the pendulum will come to “rest” on the damper. One detail I nearly missed is that thin piece of cork that is glued to the end of the damper rod (see detail image at right). The cam moves an arm up and down; the actual damper is the brass rod that extends to the right from the arm. The keying lever in the photo is at rest against the thin piece of cork (the lever end is directly below the screw head at the top right quandrant of the photo).
The base of this key is wood and some sort of phenolic or bakelite. The photo of the bottom of the key shows what looks like a mishmash of levers and rods. I haven’t traced each one and determined its function (real or presumed). Judging by the rough hewn appearance of the base, we can probably assume the key is a homebrew one, though I’m left wondering who was the talented craftsman who designed and built this key.
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