60's crystal radio (CB22171E)

Found in an English publication from the 1960s, this circuit uses period components, including the commercial grade coil.

9 to 14 V adjustable power supply (CB8504E)
This source was found in Philips' 60s documentation. The transistors are from the era and the...
Indicator for previous tachometer (CB25052E)
This circuit is the digital indicator for the previous circuit and can be used with similar...
Regulated charge pump (CB8716E)
Found in a 90s Electronic Design, this circuit operates with Maxim components of the time. The...