I've been goofing with my new Mac Key in between Christmas parties and shopping trips this weekend, and the old key has a few surprises.
I was trying to improve the dash lever action — without making the pivot for that lever so loose it fell out of its damaged pivot — and was reasonably successful. The lever had been so tight it sometimes shifted the key a bit when you had to send multiple dashes. The return spring on the dash lever looked factory, though it was made of some very heavy gauge wire. Judging from other photos of Mac Keys, I suspect the heavy spring is indeed original. Anyway, adjusting the lever tension for a snappy return (with the stiff pivot) made the dash lever really, really sluggish, contributing to the “scooting key” problem.
I was able to adjust the pivot for a little less pressure, improving the dash lever action enough so I could use it on the air without worrying about the key scooting around (this is a 4-pound key, it normally stays whereever it sits).
I was testing the key with some off-the-air test QSOs and found the damper to be rather loud and clunky. The problem was the damper wheel. The damper holds the wheel in a metal fork. About 1/3 of the wheel sticks out, and the damper wheel should jiggle freely in order to dampen the keying lever when it slaps home.
The damper wheel was stuck up inside the metal fork assembly, basically sitting there flush. The keying lever hit the edge of the damper wheel, but the wheel was lodged tight, so the “thunk” was created by the lever hitting a solid damper assembly.
On closer inspection, the wheel simply needs to be cleaned up. but the bigger surprise was something I had totally missed — I had looked at but never noticed the wire clip on the damper that was there to hold the damper against the stop when you wanted to turn the Mac Key on its side and operate it as a straight key.
Frankly, I had never seen one, and I never knew how it was stowed. It really is hidden well, and until I began to examien the damper assembly up close, I never noticed the clip was there. In my earlier posts, I had stated it was missing that clip. Maybe I need new glasses, eh??
I have to give McElroy's designers their props — the way they designed the damper and the clip was ingenious. I assumed the wire clip was lost to history, but I suspect that more keys than not probably have the clip in place. When not in use the clip is virtually invisible and protected from damage.
I'm anxious to make a new lower dash pivot for this key, I think once that's done it'll improve the action significantly. It's plays pretty well now, but I wouldn't use it without keeping one hand on the base in case it started to scoot a bit.
I'm out of here for now … 73.