Relative impedance meter (CB7487E)

Found in a 1960 Sylvania manual, this circuit can be implemented with a modern equivalent transistor like the BC558.

SP3042 Discrete Bidirectional TVS Series
April 2017 - Littelfuse's new two-way discrete TVS diodes for protection against ESD up to 30 kV...
NAB Amplifier (CB22148E)
Found in an English documentation from 1989, this circuit is intended for equalization of cassette...
Signal Follower 4001 (CB5890E)
We can also use the 4011 on this CMOS circuit that makes use of a crystal headset. The power...