I found tis circuit in na old documentation from 1958. The circuit uses germanium transistor availble that time and hard to obtain today. The circuit is indicated for phono applications using variable reluctance transducer.
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
This is a simple 1-digit voltmeter circuit using voltage comparators. It was found in a 2004...