The integrated circuit used in this trigger is uncommon today. We found it in a documentation from the 70s. The circuit operates with signals up to 50 kHz.
This small commercial radio for the MW band with germanium transistors was found in Japanese...
This circuit is from 1992 documentation. The transistor can be a TIP42 with a good heat sink for...
This speaker overload protection circuit was found in Radio Electronics from the 1980s. The...