Found in Unitrode documentation, this oscillator uses some unusual components today such as PU and the 3 M potentiometer. The power can be made with voltages around 15 V.
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...