This 1965 circuit uses a Philips 4068 tube to measure extremely small charges. The circuit has as indicator a micro ammeter and the transistors are of the time.
This 6-transistor radio was sold in Japan in the 1960s. The super-heterodyne circuit for the OM...
We found this circuit in a 2006 documentation. The circuit has two parts: a base where we have the...
This dual-gate FET RF signal mixer circuit was found in a 1980s documentation. The circuit is...