Found in a 1968 Texas Instruments documentation this circuit uses an SCR from that time. Modern equivalent types can be used for a higher power version.
This circuit is suitable for SSB modulation and was obtained from an amateur radio documentation from...
This circuit was obtained in a 90’s Popular Electronics. The operators admit equivalents such as...
This 7400 TTL circuit has a memory, keeping the LED on when a pulse is detected. The circuit must be...