4093 Sine Square Converter (CB26335E)

Found in a Popular Electronics from the 90s, this circuit operates up to about 5 MHz input.

Battery Monitor (CB6398E)
This circuit was originally found in a Philips documentation from 1969. It is intended for sensing...
RCA Radio Model 7BT 9J (CB18442E)
This 6-transistor transistor radio is a RCA product from the 1960s. The circuit is powered by a 9...
9 V and 1.5 V battery test (CB24457E)
We found this circuit in documentation from the 90s. Instead of a voltmeter, you can use the...