The signals from this circuit obtained from the 1965 Radio Shack documentation are picked up from a medium wave receiver. L1 and L2 have 80 to 100 turns of yarn 28 on a ferrite rod.
This circuit with TTL output was found in a 1968 EEE. The transistor can be of general use. The...
This high input impedance circuit makes use of two operational ones that are still common. The...
Found in American documentation from 1969, this circuit operates in the frequency range 10 to 150...