Found in a 90s Popular Electronics, this circuit makes use of power MOSFETs. Equivalent MOSFETs can be used. The circuit acts as a shield.
This circuit of a 1978 American publication monitors a telephone line by triggering a relay. The...
This interesting FET-tester circuit was obtained from an old American documentation. The bipolar...
This old VHF TV booster that also serves FM was found in Radio Electronics magazine from April...