This input circuit for an oscilloscope was found in Radio Electronics from the 90s. The operating circuit is from that time, and a modern equivalent can be tried out.
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...