Metal locator (CB7506E)

This simple metal detector was found in a 1960 Sylvania transistor manual. The phone must be high impedance or crystal.

Electronic Cricket (CB16746E)
This cricket circuit obtained in a 1992 documentation has an amplifying stage that, however, takes...
Commercial Radio TR 63 (CB18834E)
This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455...
12 V x 5 A Power Supply (CB1508E )
This traditional configuration from a simple 12 V source is from a 1977 publication. The...