This circuit was obtained in a QST magazine from the 90s. The circuit makes use of components that are uncommon today. The circuit includes a gain selection switch.
Nixie-type displays are no longer used except for assemblies of people who like old technology. The...
A NOR gate can be improvised using one NAND gate of a 4011 as shown here. The diodes are...
This circuit is from an American 80's documentation. The integrated circuit is of the time and is no...