Using JFETs, this circuit from a 90’s American documentation can generate signals of 0.15 Hz. The JFET can be of any general-purpose type like the BF245 or MPF102.
Found in a 1980s amateur radio QST magazine, this is the conventional circuit of a medium-wave...
Based on a 555, this 80's American documentation circuit detects the voltage of a battery and can then...
This is one of the possible transistor preamp configurations in the common emitter configuration. The...