4093 Sine Square Converter (CB26335E)

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

Regulated power supply (CB23598E)
Using power transistors of the time, this source was published in Radio Electronics magazine in...
Frequency Selectable Oscillator (CB22253E)
Found in an American publication on transistors from the 60's, this circuit uses a transistor...
Sonic Relay (CB18829E)
This circuit is from a very old publication, from the 60s. It uses germanium transistors from the...