15V Negative Regulator (CB5465E)

This circuit is from an old documentation. Integrated circuit 723 is not common today. The power transistor shall be fitted with a heat sink.

AFSK Tone Generator (CB4201E)
We find this encoding circuit in an American 1980s amateur radio documentation. The circuit can be...
Microsemi Le87557 Differential Amplifier
Microsemi Le87557 Differential Amplifier Mouser Electronics offers Microsemi Le87557 single...
Three Input Mixer (CB4999E)
This circuit was found in a Spanish magazine that no more existis, Mundo Electrónico, in a...