This circuit was found in a British documentation from 1969. It can be implemented with modern transistors. The pass band is 6 MHz.
Home automation systems are becoming smarter and more connected with the launch of every new...
April 2017 - Mouser Electronics already stocks the new Broadcom APDS-9500 proximity and gesture...
This circuit is a from publication 1980, but still can be mounted with BC548 transistors for Q1...