This CW circuit was found in a Radio Amateur Today from the 890s. The CMOS circuit must be powered by an isolated source and has different dash and dot timings.
This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio...
This circuit indicates when the monitored voltage drops below the value determined by the divider...
This circuit, from a 1975 Motorola manual, uses a power Darlington transistor of the time. We can...