This circuit was found in a 1969 US documentation. It provides a signal that can be externally programmed as suggested circuits. The circuit can be used as a shield.
This circuit is from a Ferranti publication of 1968. The circuit generates a signal according to the...
This circuit was found on an 80's Ham Radio. The transistor admits equivalent. The circuit can...
This circuit is from a Hands-On Electronics from the 90s. The integrated amplifiers used are well...