Mini solar organ (CB20506E)

This circuit was found in an old documentation and can be powered by a solar panel. The touch resistor is a nichrome wire.

Crystal oscillator (CB24563E)
This circuit, which can function as a small transmitter, was found in the July 1978 issue of Radio...
Three Input Mixer (CB4999E)
This circuit was found in a Spanish magazine that no more existis, Mundo Electrónico, in a...
Precision Current Source (CB24752E)
Using a transconductance operational amplifier, this circuit was found in July 1983 Radio...