This circuit was obtained in a QST magazine from the 90s. The circuit makes use of components that are uncommon today. The circuit includes a gain selection switch.
This circuit obtains phase-inverted signals from a single signal. The circuit uses two LM741...
This circuit was found in a 1963 magazine. The magazine no longer exists, but the circuit can be...
a This circuit was obtained from a 1978 Practical Wireless. It causes a low-power 1.5V lamp to...