Found in a 1966 publication, this circuit is a simple version of a field strength meter. The diode is a general-purpose germanium type.
The 4093 or any other NAND gate can be used for the very sensitive configuration of a R-S...
This circuit was obtained from Radio Electronics magazine of June 1964. The SCR may be a modern...
This circuit causes an LED to flash if the monitored voltage exceeds the value set in the pot. The...