CMOS keyers

I have some kind of passion for keyers. I have built many of them, much more than I would need. The outcome is almost the same but

schematic diagrams and components used vary..

The challenge is to make them error free. Difficult thing often has been to get dots 100% correct and not dash instead.

Timing and signal levels have to be correct with all resistance values of the paddle contacts, even if the contact is noisy.

CMOS is ideal for building CW keyers if you do not prefer PIC processors or other soft ware based solutions.

Enclosed are two CMOS keyers which I have built. The 2009 version is more clean but both should be error free.

Pekka

11.12.2009