This is the best handling straight key I have in the shack. It's a Signal Electric M100, and was made somewhere around 1939-1941, as best as I can tell from markings and catalog info. This one is equipped with a leaf spring, instead of the typical coil spring, and I've not been able to find any of the Signal Electric "J-38" style keys like that...so I'm a bit baffled by that part. If it was converted by someone, they did a great job: the lever spring force feels perfect and is very easy on the wrist.
I've not tried to clean it, other than to brush the dust off of it. It looks to be all solid brass (not brass plated steel, as it's non-magnetic), with a plated steel lever and flat top knob.
Signal Electric M-100 with leaf spring...
Close up shot of the leaf spring setup...
This leaf spring arrangement is a mystery to me, but it works great!
You can faintly see the "SIGNAL ELECTRIC MFG CO. MENOMINEE, MICH" markings in base, under the "up" adjusting screw contact point.
Dave WB4IUY
