This circuit is from a 1980s Signetics documentation. The circuit separates the modulation signal from a carrier. The used components are not common today.
This good gain antenna up to 30 MHz was found in an American 1990s documentation. The circuit can be...
This circuit was found in an English magazine from 1973. The magazine no longer exists, but the...
This is a battery powered 3W power amplifier using germanium transistors. The circuit is from an...