CMOS Keyer

2023-11-11

Micro-controller keyers are  too easy to have fun. YASIC project with the Atmel chip is surely the best result.

However it's much more interesting old style logic circuit. After few research on the internet I have found this to be funny enough . The very first project I have found it here https://www.qsl.net/pa2ohh/iambic.htm

The original design is from HB9ABO, page 70 on Ham Radio January 1979 and can easily be found on the internet.

(https://www.worldradiohistory.com/Archive-DX/Ham%20Radio/70s/Ham-Radio-197901.pdf)

This was the old schematic:

New schmatic from  PA2OO was slightly different and can do squeeze keyng too

Next step to learn how it works is simulate logic behavior.

Logisym is a free very nice digital simulator  can be found here https://github.com/logisim-evolution/logisim-evolution

Here is a circuit simulation with different key function for semplicity in logic essential

A clock has been inserted as master time. Can be done in various way as for example by an ne555. 

Can see dash and dot pin set to one in squeeze mode and the output resulting streem of