This modulator circuit for low intensity signals is from old documentation. The integrated circuit used is uncommon today. The circuit operates with signals up to 2MHz.
This circuit is from 1989 documentation. It uses the TDA2002 as a modulator and the unusual power...
This configuration is suggested by Mullard (Philips) in an old manual of 555 integrated circuits....
The figure shows how to use a CMOS amplifier as a crystal-controlled oscillator. The circuit is...