This circuit uses a crystal phone and can be built with more modern transistors like the BC548. The original circuit is from a 1979 publication and is powered with only two AA or AAA batteries.
This circuit was found in an old British publication from 1976. It must be powered with 5 V and...
This midrange filter for sound systems was found in the May 1988 issue of Radio Electronics...
January 2017 - Mouser Electronics already has in stock the Epson TCXO TG2016 crystal oscillators for use...