Stereo FM Transmitter (CB8459E)

This circuit was found in a 90s Radio Electronics. The FM encoder or multiplexer is an uncommon component today.

Universal Battery Test (CB21347E)
This circuit was obtained from an English circuit manual. Components are common and LEDs can be 3...
Linear VCO (CB9429E)
Found in a 90's EDN, this circuit generates signals in the frequency range given by the graph. The...
100 kHz to 1 MHz Oscillator (CB12815E)
This circuit can generate signals from 100 kHz to 1 MHz depending on the L1 coil. For the medium...