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.
Found in Radio Electronics from the 90s, this circuit is based on the 555 directly feeding a small...
This 1 MHz oscillator was found in an Electronics World of 1969. The circuit uses a...
This circuit was found in a 1966 General Electric documentation. The circuit makes use of PUTs...