We found this circuit in a 1985 documentation. The transformer is an old TV flyback that has an exposed part of the core, where 10 to 20 turns of common wire are wrapped.
This two-tone decoder has a bandwidth of 24%. The circuit is from a 1994 Electronics Now. The...
This circuit was found in a Popular Electronics of the 1980s. The microammeter may be the lowest...
This sensitive circuit can be designed with FETs such as BF245 and MPF102. The sensor is a silicon...